JP6569349B2 - Magnetoresistive device - Google Patents

Description

The present invention relates to a magnetoresistive effect device using a magnetoresistive effect element.

(Description of ferromagnetic resonance)
Since the magnetization of the ferromagnetic material moves relative to the applied magnetic field, when a vibrating external AC magnetic field is applied, the magnetization of the ferromagnetic material vibrates according to the frequency of the external AC magnetic field. For example, as described in Non-Patent Document 1, it is known that when the frequency of the applied external AC magnetic field is close to the resonance frequency of the ferromagnetic material, the magnetization amplitude of the vibrating ferromagnetic material becomes very large. This phenomenon is called ferromagnetic resonance (FMR). In ferromagnetic resonance, the spectrum of the amplitude of magnetization of the ferromagnetic material with respect to the frequency of the applied external AC magnetic field has a shape having a peak at the resonance frequency.

  As a magnetoresistive effect element, a GMR (Giant Magneto Resistive Effect) element in which a nonmagnetic conductive layer as a spacer layer is sandwiched between ferromagnetic layers, or a TMR (non-magnetic insulating layer as a spacer layer is sandwiched between ferromagnetic layers). A Tunnel Magneto Resistance Effect element or the like is known. When an external AC magnetic field is applied to the magnetoresistive effect element, the angle between the magnetization of the magnetization fixed layer and the magnetization of the magnetization free layer changes according to the change in the magnetization of the magnetization free layer, and the magnetoresistance effect The resistance of the element changes. Therefore, the spectrum of the resistance change of the magnetoresistive element with respect to the frequency of the applied external alternating magnetic field has a shape having a peak at the resonance frequency of magnetization of the magnetization free layer. Further, the half width of this spectrum is, for example, several tens of MHz to several GHz.

(Description of spin injection magnetization oscillation element)
On the other hand, when a direct current having a current density equal to or higher than the oscillation threshold current density flows through a magnetoresistive effect element such as a TMR element or a GMR element, a phenomenon is known in which the magnetization of the magnetization free layer oscillates due to spin torque. The magnetization vibration of the magnetization free layer can be output as an AC signal corresponding to the magnetization vibration frequency by the magnetoresistance effect. For example, Patent Document 1 and Patent Document 2 propose using a magnetoresistive effect element as an oscillator that applies a current having a current density equal to or higher than the oscillation threshold current density to the magnetoresistive effect element and extracts an output in a high frequency band. ing. Such a magnetoresistive effect element is particularly called a spin injection magnetization oscillation element. In the magnetization vibration due to the spin torque, the magnetization vibration frequency of the magnetization free layer is generally in a high frequency band of several to several tens GHz. Moreover, when the magnetization amplitude of the oscillating magnetization free layer is represented by a frequency spectrum, it has a shape having a peak corresponding to the resonance frequency of the magnetization of the magnetization free layer. Further, when the resistance change due to the magnetoresistive effect is taken as a frequency spectrum, the shape similarly has a peak at the resonance frequency of magnetization of the magnetization free layer. The full width at half maximum of this spectrum is, for example, several MHz to several hundred MHz, and is generally smaller than the full width at half maximum of the spectrum of resistance change due to the vibration of magnetization of the magnetization free layer due to the external AC magnetic field.

Japanese Patent No. 4767589 Patent No. 5434783

J. et al. -M. L. Beaujour et al. , J. et al. Appl. Phys. 99, 08N503 (2006)

  The spin-injection magnetization oscillating element can be used for a crystal oscillator replacement or a wireless communication transmitter. However, a high output is required for use in these applications, and existing spin-injection magnetization oscillation elements cannot satisfy this requirement. TMR elements and GMR elements have different problems as spin-injection magnetization oscillation elements because the spin-injection magnetization oscillation element cannot increase the output. The vibration of magnetization due to spin torque is characterized in that the amplitude increases as the current density of the current applied to the magnetoresistive effect element increases. However, since the GMR element has a small magnetoresistive effect, the magnetization of the magnetization free layer There is a problem that the electrical high-frequency output that can be taken out is small even if the vibration is large. On the other hand, in order to cause magnetization vibration due to spin torque, it is necessary to pass a very large current having a current density equal to or higher than the oscillation threshold current density to the magnetoresistive effect element. However, the TMR element has a small withstand voltage and a large current density. If the current is applied, the element is broken. Therefore, there is a problem that the magnetization of the magnetization free layer cannot be greatly oscillated by supplying a current having a large current density. An object of the present invention is to provide a magnetoresistive effect device capable of realizing a high oscillation output while keeping the oscillation threshold current density small.

In order to achieve the above object, a magnetoresistive device according to the present invention includes a first magnetization free layer, a first magnetization fixed layer, and a gap between the first magnetization free layer and the first magnetization fixed layer. A first magnetoresistive element having a first spacer layer disposed; a second magnetization free layer; a second magnetization fixed layer; and the second magnetization free layer and the second magnetization fixed layer. A second magnetoresistive element having a second spacer layer disposed therebetween, a magnetic field application mechanism for applying an external magnetic field to the first magnetization free layer and the second magnetization free layer, The first magnetization free layer and the second magnetization free layer are magnetically coupled, and a straight line parallel to the magnetization direction of the first magnetization fixed layer is applied to the first magnetization free layer. Than the angle formed by a straight line parallel to the direction of the external magnetic field to be generated. An angle formed by a straight line parallel to the direction and a straight line parallel to the direction of the external magnetic field applied to the second magnetization free layer is large, and the first magnetoresistive element has an oscillation threshold current density equal to or greater than A first characteristic is that a current having a current density of 1 is applied.

In the present invention, “an angle formed by a straight line parallel to the magnetization direction and a straight line parallel to the direction of the external magnetic field” is smaller than an angle formed by a straight line parallel to the magnetization direction and a straight line parallel to the direction of the external magnetic field. This is the angle.

In the magnetoresistive effect element, the oscillation threshold current density decreases as the angle formed by the straight line parallel to the magnetization direction of the magnetization fixed layer and the straight line parallel to the direction of the external magnetic field applied to the magnetization free layer decreases. In addition, the magnetoresistive effect element has a resistance change to the vibration of the magnetization of the magnetization free layer as the angle between the line parallel to the magnetization direction of the magnetization fixed layer and the line parallel to the direction of the external magnetic field applied to the magnetization free layer increases. Becomes larger. Therefore, according to the magnetoresistive effect device having the above characteristics, in the first magnetoresistive effect element, a straight line parallel to the magnetization direction of the magnetization fixed layer and a straight line parallel to the direction of the external magnetic field applied to the magnetization free layer are formed. An oscillation threshold current density becomes small because an angle is smaller than a 2nd magnetoresistive effect element. By causing a current having a current density equal to or higher than the oscillation threshold current density to flow through the first magnetoresistive effect element, the magnetization of the first magnetization free layer can be oscillated, and accordingly, the first magnetization free layer and The magnetization of the magnetically coupled second magnetization free layer also vibrates. In the second magnetoresistive effect element, the angle formed by the straight line parallel to the magnetization direction of the magnetization fixed layer and the straight line parallel to the direction of the external magnetic field applied to the magnetization free layer is greater than that of the first magnetoresistive effect element. Is larger, the resistance change with respect to the vibration of the magnetization of the second magnetization free layer becomes larger, so that a high oscillation output can be obtained from the second magnetoresistance effect element. Thus, a high oscillation output can be obtained from the second magnetoresistive element while suppressing the oscillation threshold current density of the first magnetoresistive element.

  Furthermore, the magnetoresistive effect device according to the present invention is characterized in that the first magnetoresistive effect element and the second magnetoresistive effect element are electrically independent.

  According to the magnetoresistive effect device having the above characteristics, the first magnetoresistive effect element and the second magnetoresistive effect element are electrically independent from each other. A current can be applied to each element under optimum conditions.

  Furthermore, the magnetoresistive effect device according to the present invention is characterized in that the first magnetoresistive effect element and the second magnetoresistive effect element are electrically connected in parallel.

  According to the magnetoresistive effect device having the above characteristics, the first magnetoresistive effect element and the second magnetoresistive effect element are electrically connected in parallel, thereby suppressing the number of power supplies to which current is applied. it can.

  Furthermore, the magnetoresistive effect device according to the present invention is characterized in that the first magnetoresistive effect element and the second magnetoresistive effect element are electrically connected in series.

  According to the magnetoresistive effect device having the characteristics described above, the structure of the first magnetoresistive effect element and the second magnetoresistive effect element being electrically connected in series facilitates the element fabrication process. The number of power supplies to which current is applied can be suppressed.

  Furthermore, in the magnetoresistive effect device according to the present invention, the distance between the first magnetization free layer and the second magnetization free layer with respect to the distance between the first magnetization free layer and the second magnetization fixed layer. The fifth feature is that the second magnetoresistive element is arranged in the in-plane direction of the first magnetoresistive element so that the smaller is smaller.

  According to the magnetoresistive effect device having the above characteristics, the distance between the first magnetization free layer and the second magnetization free layer is smaller than the distance between the first magnetization free layer and the second magnetization fixed layer. By arranging the first magnetoresistive effect element and the second magnetoresistive effect element as described above, the magnetic coupling between the first magnetization free layer and the second magnetization free layer can be strengthened. Furthermore, by arranging the second magnetoresistive element in the in-plane direction of the first magnetoresistive element, the magnetic coupling between the first magnetization free layer and the second magnetization free layer is further enhanced. can do.

  Furthermore, in the magnetoresistive effect device according to the present invention, the distance between the first magnetization free layer and the second magnetization free layer with respect to the distance between the first magnetization free layer and the second magnetization fixed layer. The sixth feature is that the second magnetoresistive element is arranged in the direction perpendicular to the film surface of the first magnetoresistive element so as to be smaller.

  According to the magnetoresistive effect device having the above characteristics, the distance between the first magnetization free layer and the second magnetization free layer is smaller than the distance between the first magnetization free layer and the second magnetization fixed layer. By arranging the first magnetoresistive effect element and the second magnetoresistive effect element as described above, the magnetic coupling between the first magnetization free layer and the second magnetization free layer can be strengthened. Furthermore, the element manufacturing process can be facilitated by disposing the second magnetoresistive element in the direction perpendicular to the film surface of the first magnetoresistive element.

  The magnetoresistive effect device according to the present invention further includes a plurality of the second magnetoresistive effect elements, and the second magnetization of each of the first magnetization free layer and the plurality of second magnetoresistive effect elements. A seventh feature is that the free layer is magnetically coupled.

  According to the magnetoresistive effect device having the above characteristics, the second magnetoresistive effect elements are electrically connected to each other, and the outputs from the respective second magnetoresistive effect elements are added together, so that higher oscillation is achieved. Output can be obtained.

ADVANTAGE OF THE INVENTION According to this invention, the magnetoresistive effect device which can implement | achieve a high oscillation output, suppressing oscillation threshold current density small can be provided.

It is the schematic of the magnetoresistive effect device of 1st Embodiment. In the first embodiment, the magnetizations of the first magnetoresistive element and the second magnetoresistive element when a current having a current density equal to or higher than the oscillation threshold current density is not applied to the first magnetoresistive element. It is a schematic diagram of a state. In the first embodiment, the magnetization states of the first magnetoresistive element and the second magnetoresistive element when a current having a current density equal to or higher than the oscillation threshold current density is applied to the first magnetoresistive element. FIG. It is a schematic diagram of the circuit containing the magnetoresistive effect device of 1st Embodiment. It is a figure which shows the time waveform of the voltage output at the output terminal of 1st Embodiment. It is a graph which shows the dependence of the oscillation threshold current density of a 1st magnetoresistive effect element with respect to the angle which the external magnetic field applied to a 1st magnetization free layer and the magnetization of a 1st magnetization fixed layer make. It is a graph which shows the dependence of the resistance of a 2nd magnetoresistive effect element with respect to the angle which the magnetization of a 2nd magnetization free layer and the magnetization of a 2nd magnetization fixed layer form. It is the schematic of the magnetoresistive effect device of 2nd Embodiment. In the second embodiment, magnetization of the first magnetoresistive element and the second magnetoresistive element when a current having a current density equal to or higher than the oscillation threshold current density is not applied to the first magnetoresistive element. It is a schematic diagram of a state. In the second embodiment, the magnetization states of the first magnetoresistive element and the second magnetoresistive element when a current having a current density equal to or higher than the oscillation threshold current density is applied to the first magnetoresistive element. FIG. It is the schematic of the magnetoresistive effect device of 3rd Embodiment. It is a schematic diagram of the circuit containing the magnetoresistive effect device of 3rd Embodiment. It is the schematic of the magnetoresistive effect device of 4th Embodiment. It is a schematic diagram of the circuit containing the magnetoresistive effect device of 4th Embodiment. It is the schematic of the magnetoresistive effect device of 5th Embodiment. It is a schematic diagram of the circuit containing the magnetoresistive effect device of 5th Embodiment.

  Preferred embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those that are equivalent. Furthermore, the constituent elements described below can be appropriately combined. In addition, various omissions, substitutions, or changes of the components can be made without departing from the scope of the present invention.

  In FIG. 1, the schematic of the magnetoresistive effect device 100 of 1st Embodiment is shown. The magnetoresistance effect device 100 includes a first magnetoresistance effect element 2 and a second magnetoresistance effect element 7. The first magnetoresistive effect element 2 includes a first magnetization free layer 2a, a first magnetization fixed layer 2c, and a first magnetization fixed layer 2c disposed between the first magnetization free layer 2a and the first magnetization fixed layer 2c. The spacer layer 2b functions as a TMR element or a GMR element. The second magnetoresistance effect element 7 includes a second magnetization free layer 7a, a second magnetization fixed layer 7c, and a second magnetization fixed layer 7c disposed between the second magnetization free layer 7a and the second magnetization fixed layer 7c. The spacer layer 7b and functions as a TMR element or a GMR element.

  As shown in FIG. 1, the first magnetoresistance effect element 2 further includes a first antiferromagnetic layer 2d, and the second magnetoresistance effect element 7 further includes a second antiferromagnetic layer 7d. ing.

  As shown in FIG. 1, in the magnetoresistive effect device 100, in order to apply a current to the first magnetoresistive effect element 2, first upper electrodes are formed on both sides in the stacking direction of the first magnetoresistive effect element 2. 1 and the first lower electrode 4 are connected. Further, in order to apply a current to the second magnetoresistive effect element 7 and to extract an output, the second upper electrode 6 and the second lower electrode are disposed on both sides of the second magnetoresistive effect element 7 in the stacking direction. 8 is connected.

Further, as shown in FIG. 1, the first magnetoresistive element 2 and the second magnetoresistive element 7 are arranged adjacent to each other on the same plane with the insulator 5 interposed therebetween. A second magnetoresistive element 7 is arranged in the in-plane direction of the magnetoresistive element 2. Further, the first magnetoresistive element 2 and the second magnetoresistive element 7 are configured in the same order from the bottom, such as an antiferromagnetic layer, a magnetization fixed layer, a spacer layer, and a magnetization free layer. . Thus, the distance between the first magnetization free layer 2a and the second magnetization free layer 7a is smaller than the distance between the first magnetization free layer 2a and the second magnetization fixed layer 7c. The 1st magnetoresistive effect element 2 and the 2nd magnetoresistive effect element 7 are arrange | positioned. The first magnetization free layer 2a and the second magnetization free layer 7a are magnetically coupled, and the magnetization 2e of the first magnetization free layer 2a and the magnetization 7e of the second magnetization free layer 7a are magnetic. Is bound to.

The first upper electrode 1, the first magnetoresistive effect element 2, and the first lower electrode 4 are composed of the second upper electrode 6, the second magnetoresistive effect element 7, and the second lower electrode by an insulator 5. 8 and electrically isolated.

  In addition, the magnetoresistive effect device 100 includes a magnetic field application mechanism 3 that applies an external magnetic field to the first magnetization free layer 2a and the second magnetization free layer 7a. The magnetic field application mechanism 3 is, for example, a permanent magnet.

The first magnetization free layer 2a and the second magnetization free layer 7a are layers exhibiting ferromagnetism, and the material thereof is, for example, Fe, Co, Ni, FeCo or CoFeB in order to obtain a high magnetoresistance change rate. It is a high spin polarizability material that is a ferromagnetic material, and may contain Pt, Pd, etc. in order to have perpendicular magnetic anisotropy. The first magnetization free layer 2a and the second magnetization free layer 7a may be an in-plane magnetization film having magnetic anisotropy in the in-plane direction, or a perpendicular magnetization film having magnetic anisotropy in the direction perpendicular to the film plane. good. When the first magnetoresistive element 2 or the second magnetoresistive element 7 is made to function as a GMR element, the first spacer layer 2b or the second spacer layer 7b is a nonmagnetic conductive layer, and its material is, for example, Cu or Ag. When the first magnetoresistive element 2 or the second magnetoresistive element 7 functions as a TMR element, the first spacer layer 2b or the second spacer layer 7b is a nonmagnetic insulating layer, and its material Is, for example, AlO _x (aluminum oxide), MgO (magnesium oxide), MgAl ₂ O ₄ or the like. The first magnetization fixed layer 2c and the second magnetization fixed layer 7c are layers exhibiting ferromagnetism, and the material thereof is, for example, Fe, Co, Ni, FeCo or CoFeB in order to obtain a high magnetoresistance change rate. It is a high spin polarizability material that is a ferromagnetic material, and may contain Pt, Pd, etc. in order to have perpendicular magnetic anisotropy. The first magnetization fixed layer 2c and the second magnetization fixed layer 7c may be in-plane magnetization films having magnetic anisotropy in the in-plane direction of the film, or perpendicular magnetization films having magnetic anisotropy in the direction perpendicular to the film plane. Although it is good, it is preferable to have the same magnetic anisotropy as that of the corresponding magnetization free layer. The material of the first antiferromagnetic layer 2d and the second antiferromagnetic layer 7d is, for example, an antiferromagnetic material such as PtMn, IrMn, or FeMn so as to exhibit an exchange bias effect. The blocking temperature of the first antiferromagnetic layer 2d is lower than that of the second antiferromagnetic layer magnet 7d. For example, the material of the first antiferromagnetic layer 2d can be IrMn, and the material of the second antiferromagnetic layer magnet 7d can be PtMn. Further, the same antiferromagnetic material is used for the first antiferromagnetic layer 2d and the second antiferromagnetic layer magnet 7d, and the thickness of the first antiferromagnetic layer 2d is changed to the second antiferromagnetic layer film. The blocking temperature can also be made different by making it thinner than the thickness. The material of the permanent magnet that constitutes the magnetic field application mechanism 3 is, for example, CoPt or FePt. Furthermore, the material of the insulator 5 is, for example, AlO _x (aluminum oxide), MgO (magnesium oxide), or SiO _x (silicon oxide).

  FIG. 2 shows the first embodiment when a current having a current density equal to or higher than the oscillation threshold current density is not applied to the first magnetoresistive element 2 and the second magnetoresistive element 7 in the first embodiment. 6 is a schematic diagram of magnetization states of the magnetoresistive effect element 2 and the second magnetoresistive effect element 7. FIG. 3 shows that in the first embodiment, a current having a current density equal to or higher than the oscillation threshold current density is applied to the first magnetoresistance effect element 2, while the oscillation threshold current is applied to the second magnetoresistance effect element 7. 6 is a schematic diagram of magnetization states of the first magnetoresistance effect element 2 and the second magnetoresistance effect element 7 when a current having a current density equal to or higher than the density is not applied. FIG. Here, an example in which the first magnetization free layer 2a, the second magnetization free layer 7a, the first magnetization fixed layer 2c, and the second magnetization fixed layer 7c are in-plane magnetization films will be described. 2 and 3, the magnetization vectors of the first magnetization free layer 2a, the first magnetization fixed layer 2c, the second magnetization free layer 7a, and the second magnetization fixed layer 7c are respectively shown by using white arrows. , Magnetization 2e of the first magnetization free layer 2a, magnetization 2f of the first magnetization fixed layer 2c, magnetization 7e of the second magnetization free layer 7a, and magnetization 7f of the second magnetization fixed layer 7c.

The first magnetoresistive element 2 and the second magnetism when a current having a current density equal to or higher than the oscillation threshold current density is not applied to the first magnetoresistive element 2 and the second magnetoresistive element 7. The magnetization state of the resistance effect element 7 will be described below. An external magnetic field 3a is applied from the magnetic field application mechanism 3 to the first magnetization free layer 2a and the second magnetization free layer 7a. The magnetization 2e of the first magnetization free layer 2a and the magnetization 7e of the second magnetization free layer 7a are oriented in the same direction as the external magnetic field 3a.

The magnetization 2f of the first magnetization fixed layer 2c is fixed by the exchange bias effect with the first antiferromagnetic layer 2d, and is parallel and opposite to the external magnetic field 3a. Further, the magnetization 7f of the second magnetization fixed layer 7c is fixed by the exchange bias effect with the second antiferromagnetic layer 7d, and faces the direction orthogonal to the external magnetic field 3a. Thus, the angle formed by the straight line 2g parallel to the direction of the magnetization 2f of the first magnetization fixed layer 2c and the straight line 3b parallel to the direction of the external magnetic field 3a applied to the first magnetization free layer 2a The angle formed by the straight line 7g parallel to the direction of the magnetization 7f of the second magnetization fixed layer 7c and the straight line 3b parallel to the direction of the external magnetic field 3a applied to the second magnetization free layer 7a is large.

  A method of fixing the magnetization 2f of the first magnetization fixed layer 2c and the magnetization 7f of the second magnetization fixed layer 7c will be described. A first antiferromagnetic layer 2d, a first magnetization fixed layer 2c, a first spacer layer 2b, a first magnetization free layer 2a, a second antiferromagnetic layer 7d, a second magnetization fixed layer 7c, After the second spacer layer 7b and the second magnetization free layer 2a are formed, annealing is performed twice in the magnetic field. In the first annealing treatment, the annealing temperature is set higher than the blocking temperature of the first antiferromagnetic layer 2d and the blocking temperature of the second antiferromagnetic layer 7d. In the first annealing process, an annealing magnetic field is applied to the entire laminated film in a direction orthogonal to the external magnetic field 3a during annealing and cooling from the annealing temperature. After the first annealing treatment, the magnetization 2f of the first magnetization fixed layer 2c and the magnetization 7f of the second magnetization fixed layer 7c are respectively the first antiferromagnetic layer 2d and the second antiferromagnetic layer 7d. Both are fixed in a direction orthogonal to the external magnetic field 3a by the exchange bias effect. Next, a second annealing process is performed, and the annealing temperature at this time is lower than the blocking temperature of the second antiferromagnetic layer 7d but higher than the blocking temperature of the first antiferromagnetic layer 2d. In the second annealing treatment, during annealing and cooling from the annealing temperature, an annealing magnetic field is applied to the entire laminated film in parallel and in the opposite direction to the external magnetic field 3a. After the second annealing treatment, the magnetization 2f of the first magnetization fixed layer 2c is fixed in a direction parallel to and opposite to the external magnetic field 3a by the exchange bias effect with the first antiferromagnetic layer 2d. The direction in which the magnetization 7f of the magnetization fixed layer 7c is fixed is not changed. After the annealing process twice, the magnetization 2f of the first magnetization fixed layer 2c is fixed in a direction parallel to and opposite to the external magnetic field 3a, and the magnetization 7f of the second magnetization fixed layer 7c is orthogonal to the external magnetic field 3a. Fixed in direction.

  In FIG. 4, the schematic diagram of the circuit containing the magnetoresistive effect device 100 of 1st Embodiment is shown. In order to apply a direct current to the first magnetoresistive effect element 2, the first input terminal 9 and the first upper electrode 1 are electrically connected, and the first lower electrode 4 is connected to the ground. Yes. In order to apply a direct current to the second magnetoresistive effect element 7, the second input terminal 12 is electrically connected to the second upper electrode 6 via the direct current terminal of the bias tee 10. In addition, the output terminal 11 is electrically connected to the second upper electrode 6 via the AC terminal of the bias tee 10 in order to take out the output from the second magnetoresistive effect element 7. The second lower electrode 8 is connected to the ground. Thus, the 1st magnetoresistive effect element 2 and the 2nd magnetoresistive effect element 7 are electrically independent. The bias tee 10 prevents the direct current applied from the second input terminal 12 from being mixed into the output terminal 11, and the output generated by the second magnetoresistive element 7 is the second input terminal 12. It is provided for the purpose of preventing contamination.

  Here, the operation principle of the magnetoresistive effect device 100 of the first embodiment will be described. In FIG. 2, a direct current having a current density smaller than the oscillation threshold current density of the first magnetoresistive element 2 is applied to the first input terminal 9, and the second magnetoresistive element is applied to the second input terminal 12. 7 shows a magnetization state when a direct current having a current density smaller than the oscillation threshold current density of 7 is applied. At this time, since the magnetization 2e of the first magnetization free layer 2a does not vibrate, the magnetization 7e of the second magnetization free layer 7a also does not vibrate. As a result, no output voltage is generated at the output terminal 11. On the other hand, in FIG. 3, a current having a current density equal to or higher than the oscillation threshold current density of the first magnetoresistance effect element 2 is applied from the first input terminal 9 to the first magnetoresistance effect element 2. The magnetization state when a direct current having a current density smaller than the oscillation threshold current density of the second magnetoresistance effect element 7 is applied from the input terminal 12 to the second magnetoresistance effect element 7 is shown. When a current having a current density equal to or higher than the oscillation threshold current density is applied to the first magnetoresistive element 2, the magnetization 2e of the first magnetization free layer 2a vibrates, so that the first magnetization free layer 2a The magnetization 7e of the magnetically coupled second magnetization free layer 7a also vibrates, and as a result, a high-frequency AC output voltage (oscillation output) is generated at the output terminal 11, as shown in FIG.

The magnetoresistive effect device 100 has an angle formed by a straight line 2g parallel to the magnetization direction of the first magnetization fixed layer 2c and a straight line 3b parallel to the direction of the external magnetic field 3a applied to the first magnetization free layer 2a. Since the angle formed by the straight line 7g parallel to the magnetization direction of the second magnetization fixed layer 7c and the straight line 3b parallel to the direction of the external magnetic field 3a applied to the second magnetization free layer 7a is large, the first magnetoresistance effect The oscillation threshold current density of the element 2 can be reduced, and a high oscillation output can be obtained from the second magnetoresistance effect element 7. This point will be described in detail below. The “angle between the straight line parallel to the magnetization direction and the straight line parallel to the direction of the external magnetic field” is the smaller of the angles formed by the straight line parallel to the magnetization direction and the straight line parallel to the direction of the external magnetic field. is there.

6 shows the dependence of the oscillation threshold current density jc of the first magnetoresistance effect element 2 on the angle θ1 formed by the external magnetic field 3a applied to the first magnetization free layer 2a and the magnetization 2f of the first magnetization fixed layer 2c. It is a graph which shows sex. As shown in this graph, the oscillation threshold current density of the first magnetoresistance effect element 2 increases as the angle formed by the external magnetic field 3a and the magnetization 2f of the first magnetization fixed layer 2c approaches 0 degrees or 180 degrees. The absolute value of becomes smaller.

  FIG. 7 is a graph showing the dependence of the resistance R of the second magnetoresistance effect element 7 on the angle θ2 formed by the magnetization 7e of the second magnetization free layer 7a and the magnetization 7f of the second magnetization fixed layer 7c. The closer the angle formed between the magnetization 7e of the second magnetization free layer 7a and the magnetization 7f of the second magnetization fixed layer 7c approaches 90 degrees, the magnetization 7e of the second magnetization free layer 7a and the second magnetization fixed layer 7c The resistance change of the second magnetoresistive element 7 with respect to the change of the angle formed by the magnetization 7f becomes large. When a current having a current density equal to or higher than the oscillation threshold current density is not applied to the first magnetoresistance effect element 2, the magnetization 7e of the second magnetization free layer 7a is applied to the second magnetization free layer 7a. Strip in the same direction as the external magnetic field 3a. Here, an angle formed by the magnetization 7e of the second magnetization free layer 7a and the magnetization 7f of the second magnetization fixed layer 7c at this time is defined as an initial angle. When a current having a current density equal to or higher than the oscillation threshold current density is applied to the first magnetoresistive element 2, the second magnetization free layer 7a has a current corresponding to the oscillation of the magnetization 2e of the first magnetization free layer 2a. The magnetization 7e vibrates, and the angle formed by the magnetization 7e of the second magnetization free layer 7a and the magnetization 7f of the second magnetization fixed layer 7c also oscillates around the initial angle. As a result, the resistance value of the second magnetoresistive element 7 vibrates. Therefore, the second magnetoresistive element 7 has an initial angle closer to 90 degrees, that is, the straight line 7g parallel to the direction of the magnetization 7f of the second magnetization fixed layer 7c and the second magnetization free layer 7a. The greater the angle formed by the straight line 3b parallel to the direction of the applied external magnetic field 3a, the greater the resistance change with respect to the vibration of the magnetization 7e of the second magnetization free layer 7a, and a higher oscillation output is obtained.

  The relationship between the angle θ1 and the oscillation threshold current density jc shown in FIG. 6 also holds when the first magnetization free layer 2a and the first magnetization fixed layer 2c are both perpendicular magnetization films, and the first magnetization free This is also the case when one of the layer 2a and the first magnetization fixed layer 2c is an in-plane magnetization film and the other is a perpendicular magnetization film. Further, the relationship between the angle θ2 and the resistance R shown in FIG. 7 also holds when the second magnetization free layer 7a and the second magnetization fixed layer 7c are both perpendicular magnetization films, and the second magnetization free layer 7a and This is also true when one of the second magnetization fixed layers 7c is an in-plane magnetization film and the other is a perpendicular magnetization film.

Therefore, in the magnetoresistive effect device 100, in the first magnetoresistive effect element 2, the angle formed by the straight line parallel to the magnetization direction of the magnetization fixed layer and the straight line parallel to the direction of the external magnetic field applied to the magnetization free layer is By being smaller than the second magnetoresistance effect element 7, the oscillation threshold current density is reduced. By causing a current having a current density equal to or higher than the oscillation threshold current density to flow through the first magnetoresistive element 2, the magnetization of the first magnetization free layer 2a can be oscillated. The magnetization of the second magnetization free layer 7a magnetically coupled to the layer 2a also vibrates. In the second magnetoresistive element 7, the angle formed by the straight line parallel to the magnetization direction of the magnetization fixed layer and the straight line parallel to the direction of the external magnetic field applied to the magnetization free layer is the first magnetoresistive element. Since the resistance change with respect to the vibration of the magnetization of the second magnetization free layer 7a is increased by being larger than 2, a high oscillation output can be obtained from the second magnetoresistance effect element 7. Thus, a high oscillation output can be obtained from the second magnetoresistance effect element 7 while suppressing the oscillation threshold current density of the first magnetoresistance effect element 2 to be small.

  In particular, the TMR element has a large magnetoresistive effect and has a large resistance change with respect to the vibration of magnetization of the magnetization free layer. Therefore, the second magnetoresistive element 7 can obtain a higher oscillation output. It is preferable to use a TMR element as the magnetoresistive element 7.

  Further, in the magnetoresistive effect device 100, the first magnetoresistive effect element 2 and the second magnetoresistive effect element 7 are electrically independent from each other. A current can be applied to each of the resistance effect elements 7 under optimum conditions.

Furthermore, the magnetoresistive effect device 100 has a distance between the first magnetization free layer 2a and the second magnetization free layer 7a with respect to the distance between the first magnetization free layer 2a and the second magnetization fixed layer 7c. The second magnetoresistive effect element 7 is arranged in the in-plane direction of the first magnetoresistive effect element 2 so that becomes smaller. Therefore, the magnetic coupling between the first magnetization free layer 2a and the second magnetization free layer 7a can be strengthened. Further, by arranging the second magnetoresistive element 7 in the in-plane direction of the first magnetoresistive element 2, the magnetic coupling between the first magnetization free layer 2a and the second magnetization free layer 7a is achieved. Can be made even stronger.

Next, regarding the second embodiment, parts different from the first embodiment will be described, and the same or corresponding parts with respect to the first embodiment will be denoted by the same reference numerals, and overlapping description will be omitted as appropriate. FIG. 8 shows a schematic diagram of the magnetoresistive effect device 200 of the second embodiment. As shown in FIG. 8, in the magnetoresistive effect device 200, in order to apply a current to the first magnetoresistive effect element 2, first upper electrodes are formed on both sides in the stacking direction of the first magnetoresistive effect element 2. 1 and the first lower electrode 4 are connected. Further, in order to apply a current to the second magnetoresistive effect element 7 and to extract an output, the second upper electrode 6 and the second lower electrode are disposed on both sides of the second magnetoresistive effect element 7 in the stacking direction. 8 is connected.

Next, regarding the second embodiment, parts different from the first embodiment will be described, and the same or corresponding parts with respect to the first embodiment will be denoted by the same reference numerals, and overlapping description will be omitted as appropriate. FIG. 8 shows a schematic diagram of the magnetoresistive effect device 200 of the second embodiment. As shown in FIG. 8, in the magnetoresistive effect device 200, in order to apply a current to the first magnetoresistive effect element 2, first upper electrodes are formed on both sides in the stacking direction of the first magnetoresistive effect element 2. 1 and the first lower electrode 4 are connected. Further, in order to apply a current to the second magnetoresistive effect element 7 and to extract an output, the second upper electrode 6 and the second lower electrode are disposed on both sides of the second magnetoresistive effect element 7 in the stacking direction. 8 is connected.

Further, as shown in FIG. 8, the first magnetoresistive element 2 is arranged immediately above the second magnetoresistive element 7 with the insulator 5 interposed therebetween. The second magnetoresistive element 7 includes a second antiferromagnetic layer 7d, a second magnetization fixed layer 7c, a second spacer layer 7b, and a second magnetization free layer 7a from the second lower electrode 8 side. Consists of an ordered arrangement. On the other hand, the first magnetoresistive effect element 2 includes a first magnetization free layer 2a, a first spacer layer 2b, a first magnetization fixed layer 2c, and a first antiferromagnetic layer from the first lower electrode 4 side. It is configured in an arrangement of 2d order. That is, in the first magnetoresistance effect element 2 and the second magnetoresistance effect element 7, the arrangement order of the antiferromagnetic layer, the magnetization fixed layer, the spacer layer, and the magnetization free layer in the same direction is reversed. It has become. Thus, the distance between the first magnetization free layer 2a and the second magnetization free layer 7a is smaller than the distance between the first magnetization free layer 2a and the second magnetization fixed layer 7c. The second magnetoresistive element 7 is arranged in the direction perpendicular to the film surface of the first magnetoresistive element 2. Also, here, the first magnetization free layer 2a and the second magnetization free layer 7a are magnetically coupled, and the magnetization 2e of the first magnetization free layer 2a and the magnetization 7e of the second magnetization free layer 7a. Are magnetically coupled.

The first upper electrode 1, the first magnetoresistive effect element 2, and the first lower electrode 4 are composed of the second upper electrode 6, the second magnetoresistive effect element 7, and the second lower electrode by an insulator 5. 8 and electrically isolated.

  Furthermore, the magnetoresistive effect device 200 includes a first magnetic field application mechanism 13 that applies an external magnetic field to the first magnetization free layer 2a, and a second magnetic field application mechanism that applies an external magnetic field to the second magnetization free layer 7a. 14. The first magnetic field application mechanism 13 and the second magnetic field application mechanism 14 are, for example, permanent magnets. The material of the permanent magnet that constitutes the first magnetic field application mechanism 13 and the second magnetic field application mechanism 14 is, for example, CoPt or FePt.

  FIG. 9 shows the first embodiment when a current having a current density equal to or higher than the oscillation threshold current density is not applied to the first magnetoresistive element 2 and the second magnetoresistive element 7 in the second embodiment. 6 is a schematic diagram of magnetization states of the magnetoresistive effect element 2 and the second magnetoresistive effect element 7. FIG. FIG. 10 shows that in the second embodiment, a current having a current density equal to or higher than the oscillation threshold current density is applied to the first magnetoresistive effect element 2, while the oscillation threshold current is applied to the second magnetoresistive effect element 7. 6 is a schematic diagram of magnetization states of the first magnetoresistance effect element 2 and the second magnetoresistance effect element 7 when a current having a current density equal to or higher than the density is not applied. FIG. Here, an example in which the first magnetization free layer 2a, the second magnetization free layer 7a, the first magnetization fixed layer 2c, and the second magnetization fixed layer 7c are in-plane magnetization films will be described.

The first magnetoresistive element 2 and the second magnetism when a current having a current density equal to or higher than the oscillation threshold current density is not applied to the first magnetoresistive element 2 and the second magnetoresistive element 7. The magnetization state of the resistance effect element 7 will be described below. A first external magnetic field 13a is applied from the first magnetic field application mechanism 13 to the first magnetization free layer 2a. The magnetization 2e of the first magnetization free layer 2a is oriented in the same direction as the first external magnetic field 13a. On the other hand, a second external magnetic field 14a is applied from the first magnetic field application mechanism 14 to the second magnetization free layer 7a. The magnetization 7e of the second magnetization free layer 7a is oriented in the same direction as the second external magnetic field 14a. At this time, the directions of the first external magnetic field 13a and the second external magnetic field 14a are opposite to each other.

  The magnetization 2f of the first magnetization fixed layer 2c is fixed by the exchange bias effect with the first antiferromagnetic layer 2d, and faces in the direction parallel to and opposite to the first external magnetic field 13a. Further, the magnetization 7f of the second magnetization fixed layer 7c is fixed by the exchange bias effect with the second antiferromagnetic layer 7d, and is directed in a direction orthogonal to the second external magnetic field 14a. Thus, from the angle formed by the straight line 2g parallel to the direction of the magnetization 2f of the first magnetization fixed layer 2c and the straight line 13b parallel to the direction of the first external magnetic field 13a applied to the first magnetization free layer 2a. However, the angle formed by the straight line 7g parallel to the direction of the magnetization 7f of the second magnetization fixed layer 7c and the straight line 14b parallel to the direction of the second external magnetic field 14a applied to the second magnetization free layer 7a increases. ing. The method of fixing the magnetization 2f of the first magnetization fixed layer 2c and the magnetization 7f of the second magnetization fixed layer 7c is the same as that of the magnetoresistive effect device 100 of the first embodiment.

  The circuit connected to the magnetoresistive effect device 200 is the same as that of the first embodiment shown in FIG.

In the magnetoresistive effect device 200, unlike the magnetoresistive effect device 100 of the first embodiment, the first magnetization free layer 2a and the second magnetization free layer 7a are arranged in the direction perpendicular to the film surface. 14a is applied in the opposite direction to the external magnetic field 13a, and the magnetization 2e of the first magnetization free layer 2a and the magnetization 7e of the second magnetization free layer 7a are magnetically coupled so as to face in opposite directions.

  The magnetoresistive effect device 200 is different from the magnetoresistive effect device 100 of the first embodiment in the state of magnetic coupling between the magnetization 2e of the first magnetization free layer 2a and the magnetization 7e of the second magnetization free layer 7a. Therefore, the vibration state of the magnetization 7e of the second magnetization free layer 7a is different from the vibration of the magnetization 2e of the first magnetization free layer 2a. For example, when the magnetization 2e of the first magnetization free layer 2a vibrates clockwise, in the magnetoresistive effect device 100 of the first embodiment, the magnetization 7e of the second magnetization free layer 7a vibrates clockwise. In the magnetoresistive effect device 200, the magnetization 7e of the second magnetization free layer 7a vibrates counterclockwise. Except for the above points, the operating principle of the magnetoresistive effect device 200 is the same as that of the magnetoresistive effect device 100 of the first embodiment.

The magnetoresistive effect device 200 is similar to the magnetoresistive effect device 100 of the first embodiment in that the external magnetic field applied to the straight line 2g parallel to the magnetization direction of the first magnetization fixed layer 2c and the first magnetization free layer 2a. A straight line 7g parallel to the magnetization direction of the second magnetization fixed layer 7c and a straight line parallel to the direction of the external magnetic field 14a applied to the second magnetization free layer 7a than the angle formed by the straight line 13b parallel to the direction 13a. Since the angle formed by 14b is large, the oscillation threshold current density of the first magnetoresistance effect element 2 can be reduced, and a high oscillation output can be obtained from the second magnetoresistance effect element 7.

  Furthermore, in the magnetoresistive effect device 200, the distance between the first magnetization free layer 2a and the second magnetization free layer 7a is greater than the distance between the first magnetization free layer 2a and the second magnetization fixed layer 7c. The second magnetoresistive element 7 is arranged in the direction perpendicular to the film surface of the first magnetoresistive element 2 so as to be small. Therefore, the magnetic coupling between the first magnetization free layer 2a and the second magnetization free layer 7a can be strengthened. Furthermore, by disposing the second magnetoresistive element 7 in the direction perpendicular to the film surface of the first magnetoresistive element 2, the element manufacturing process can be facilitated.

Next, in the third embodiment, parts different from the second embodiment will be described, and the same or corresponding parts with respect to the second embodiment will be denoted by the same reference numerals, and overlapping description will be omitted as appropriate. In FIG. 11, the schematic of the magnetoresistive effect device 300 of 3rd Embodiment is shown. As shown in FIG. 11, in the magnetoresistive effect device 300, the first magnetoresistive effect element 2 and the second magnetoresistive effect element 7 are electrically connected in series. In order to apply a current to the first magnetoresistive element 2 and the second magnetoresistive element 7 and to take out an output, an upper electrode 15 is disposed above the first magnetoresistive element 2 in the stacking direction. The lower electrode 17 is connected to the lower side of the second magnetoresistive element 7 in the stacking direction.

As shown in FIG. 11, the first magnetoresistive element 2 is disposed immediately above the second magnetoresistive element 7 with the nonmagnetic conductive buffer layer 16 interposed therebetween. The material of the nonmagnetic conductive buffer layer 16 is, for example, Au, Cu, or Ag. The second magnetoresistance effect element 7 is arranged in the order of the second antiferromagnetic layer 7d, the second magnetization fixed layer 7c, the second spacer layer 7b, and the second magnetization free layer 7a from the lower electrode 17 side. It consists of On the other hand, the first magnetoresistive element 2 has a first magnetization free layer 2a, a first spacer layer 2b, a first magnetization fixed layer 2c, and a first antiferromagnetic layer from the nonmagnetic conductive buffer layer 16 side. It is configured in an arrangement of 2d order. That is, as with the magnetoresistive effect device 200 of the second embodiment, the first magnetoresistive effect element 2 and the second magnetoresistive effect element 7 have an antiferromagnetic layer, a magnetization fixed layer, a spacer layer, and a magnetization free layer. The order of the layers, viewed from the same direction, is reversed. Thus, the distance between the first magnetization free layer 2a and the second magnetization free layer 7a is smaller than the distance between the first magnetization free layer 2a and the second magnetization fixed layer 7c. The second magnetoresistive element 7 is arranged in the direction perpendicular to the film surface of the first magnetoresistive element 2. Also, here, the first magnetization free layer 2a and the second magnetization free layer 7a are magnetically coupled, and the magnetization 2e of the first magnetization free layer 2a and the magnetization 7e of the second magnetization free layer 7a. Are magnetically coupled.

FIG. 12 is a schematic diagram of a circuit including the magnetoresistive effect device 300 of the third embodiment. In order to apply a direct current to the first magnetoresistive element 2 and the second magnetoresistive element 7, the input terminal 18 and the upper electrode 15 are electrically connected, and the lower electrode 17 is connected to the ground. Yes. The direct current is applied to the first magnetoresistive effect element 2 and the second magnetoresistive effect element 7 from the input terminal 18 via the DC terminal of the bias tee 10 and the upper electrode 15. Further, in order to take out the output, the output terminal 11 is electrically connected to the upper electrode 15 via the AC terminal of the bias tee 10. Since the first magnetoresistive effect element 2 and the second magnetoresistive effect element 7 are electrically connected in series, the same current flows through each of them. The bias tee 10 is provided for the purpose of preventing the direct current applied from the input terminal 18 from mixing into the output terminal 11 and preventing the output from mixing into the input terminal 18. Other configurations of the magnetoresistive effect device 300 and the magnetization states of the first magnetoresistive effect element 2 and the second magnetoresistive effect element 7 are the same as those of the magnetoresistive effect device 200 of the second embodiment.

Here, the operation principle of the magnetoresistive effect device 300 of the third embodiment will be described. When a direct current having a current density smaller than the oscillation threshold current density of the first magnetoresistance effect element 2 and smaller than the oscillation threshold current density of the second magnetoresistance effect element 7 is applied to the input terminal 18, Since the magnetization 2e of the first magnetization free layer 2a does not vibrate, the magnetization 7e of the second magnetization free layer 7a also does not vibrate. As a result, no output voltage is generated at the output terminal 11. On the other hand, when a direct current having a current density larger than the oscillation threshold current density of the first magnetoresistance effect element 2 and smaller than the oscillation threshold current density of the second magnetoresistance effect element 7 is applied to the input terminal 18. The magnetization 2e of the first magnetization free layer 2a vibrates. For this reason, the magnetization 7e of the second magnetization free layer 7a magnetically coupled to the first magnetization free layer 2a also vibrates, and as a result, as shown in FIG. Voltage (oscillation output) is generated.

Similar to the magnetoresistive effect device 200 of the second embodiment, also in the magnetoresistive effect device 300, the straight line 2g parallel to the magnetization direction of the first magnetization fixed layer 2c and the external applied to the first magnetization free layer 2a. It is parallel to the direction of the external magnetic field 14a applied to the straight line 7g parallel to the magnetization direction of the second magnetization fixed layer 7c and the second magnetization free layer 7a than the angle formed by the straight line 13b parallel to the direction of the magnetic field 13a. Since the angle formed by the straight line 14b is large, the oscillation threshold current density of the first magnetoresistance effect element 2 can be reduced, and a high oscillation output can be obtained from the second magnetoresistance effect element 7.

Further, the magnetoresistive effect device 300 has a structure in which the first magnetoresistive effect element 2 and the second magnetoresistive effect element 7 are electrically connected in series. Therefore, the element manufacturing process is facilitated and the number of power supplies to which current is applied can be suppressed.

Next, regarding the fourth embodiment, parts different from the first embodiment will be described, and the same or corresponding parts with respect to the first embodiment will be denoted by the same reference numerals, and overlapping description will be omitted as appropriate. In FIG. 13, the schematic of the magnetoresistive effect device 400 of 4th Embodiment is shown.

In the magnetoresistive effect device 400, as shown in FIG. 13, the first magnetoresistive effect element 2 and the second magnetoresistive effect element 7 are on the same plane as the magnetoresistive effect device 100 of the first embodiment. In addition, the second magnetoresistive element 7 is disposed adjacent to the insulator 5 in the in-film direction of the first magnetoresistive element 2.

As a difference from the first embodiment, the first magnetoresistive element 2 and the second magnetoresistive element 7 are connected to a common upper electrode 15, and the first magnetoresistive element 2 is further connected. The second magnetoresistance effect element 7 is connected to a common lower electrode 17.

FIG. 14 is a schematic diagram of a circuit including the magnetoresistive effect device 400 of the fourth embodiment. In order to apply a direct current to the first magnetoresistive element 2 and the second magnetoresistive element 7, the input terminal 18 and the upper electrode 15 are electrically connected, and the lower electrode 17 is connected to the ground. Yes. That is, the first magnetoresistance effect element 2 and the second magnetoresistance effect element 7 are electrically connected in parallel. The direct current is applied to the first magnetoresistive effect element 2 and the second magnetoresistive effect element 7 from the input terminal 18 via the DC terminal of the bias tee 10 and the upper electrode 15. Further, in order to take out the output, the output terminal 11 is electrically connected to the upper electrode 15 via the AC terminal of the bias tee 10. Since the first magnetoresistive element 2 and the second magnetoresistive element 7 are electrically connected in parallel, the same voltage is applied to each of them. The bias tee 10 is provided for the purpose of preventing the direct current applied from the input terminal 18 from mixing into the output terminal 11 and preventing the output from mixing into the input terminal 18. Other configurations of the magnetoresistive effect device 400 and the magnetization states of the first magnetoresistive effect element 2 and the second magnetoresistive effect element 7 are the same as those of the magnetoresistive effect device 100 of the first embodiment.

  The operation principle of the magnetoresistive effect device 400 is the same as that of the magnetoresistive effect device 100 of the first embodiment.

Similar to the magnetoresistive effect device 100 of the first embodiment, also in the magnetoresistive effect device 400, the straight line 2g parallel to the magnetization direction of the first magnetization fixed layer 2c and the external applied to the first magnetization free layer 2a. More parallel to the direction of the external magnetic field 3a applied to the straight line 7g parallel to the magnetization direction of the second magnetization fixed layer 7c and the second magnetization free layer 7a than the angle formed by the straight line 3b parallel to the direction of the magnetic field 3a. Since the angle formed by the straight line 3b is large, the oscillation threshold current density of the first magnetoresistance effect element 2 can be reduced, and a high oscillation output can be obtained from the second magnetoresistance effect element 7.

Furthermore, the magnetoresistive effect device 400 can suppress the number of power supplies to which current is applied by electrically connecting the first magnetoresistive effect element 2 and the second magnetoresistive effect element 7 in parallel. it can.

Although the present invention has been specifically shown and described with reference to preferred embodiments thereof, the present invention is not limited to those embodiments and is within the scope of the gist of the invention described in the claims. Various changes can be made.

  For example, in the first to fourth embodiments, it is assumed that a direct current is applied to the first magnetoresistive element 2 and the second magnetoresistive element 7, but the first magnetoresistive element A pulse current or a current having a random wavelength may be applied to the second and second magnetoresistive elements 7. In this case, by using a method of combining a low-pass filter and a high-pass filter instead of the bias tee 10, the signal mixing from the second input terminal 12 (or the input terminal 18) to the output terminal 11 and the first It is possible to prevent a signal from being mixed from the second magnetoresistance effect element 7 to the second input terminal 12 (or the input terminal 18).

  Further, for example, in the first to fourth embodiments, permanent magnets are used for the magnetic field application mechanisms 3, 13, and 14, but electromagnets may be used instead. In this case, it is possible to apply a variable external magnetic field to the first magnetization free layer 2a and the second magnetization free layer 7a by changing the current passed through the electromagnet.

  Further, for example, in the first to fourth embodiments, the first antiferromagnetic layer 2d and the second antiferromagnetic layer 7d are used, but the first magnetization fixed layer 2c and the second antiferromagnetic layer 7d are not used without using them. It is also possible to configure the second magnetization fixed layer 7c with a ferromagnetic layer exhibiting a large magnetic anisotropy.

  Also, for example, in the first to fourth embodiments, the magnetization 2f of the first magnetization fixed layer 2c is fixed in a direction parallel and opposite to the external magnetic field applied to the first magnetization free layer 2a. The magnetization 7f of the second magnetization fixed layer 7c is fixed in a direction orthogonal to the external magnetic field applied to the second magnetization free layer 7a, but the magnetization fixed directions of the first and second magnetization fixed layers are However, the present invention is not limited to this. The angle formed by the straight line 2g parallel to the magnetization direction of the first magnetization fixed layer 2c and the straight line parallel to the direction of the external magnetic field applied to the first magnetization free layer 2a If the condition that the angle formed by the straight line 7g parallel to the magnetization direction of the magnetization fixed layer 7c and the straight line parallel to the direction of the external magnetic field applied to the second magnetization free layer 7c is large is satisfied, the first magnetoresistance effect The oscillation threshold current density of the element 2 can be reduced, and the second magnetism Effect which can obtain a high oscillation output from the resistive element 7 can be obtained.

  In the second embodiment, the second magnetoresistive effect element 7 is arranged in the direction perpendicular to the film surface of the first magnetoresistive effect element 2, and the first magnetoresistive effect element 2 and the second magnetoresistive effect element are arranged. 7 is electrically independent, but the second magnetoresistive element 7 is arranged in the direction perpendicular to the film surface of the first magnetoresistive element 2, and the first magnetoresistive element 2 and the second magnetoresistive element 2 These magnetoresistive effect elements 7 may be electrically connected in parallel.

  In the fourth embodiment, the second magnetoresistive effect element 7 is arranged in the in-plane direction of the first magnetoresistive effect element 2, and the first magnetoresistive effect element 2 and the second magnetoresistive effect element are arranged. 7 are electrically connected in parallel, but the second magnetoresistive element 7 is disposed in the in-film direction of the first magnetoresistive element 2, and the first magnetoresistive element 2 and The second magnetoresistance effect element 7 may be electrically connected in series.

  In the first to fourth embodiments, one second magnetoresistive element 7 is arranged for one first magnetoresistive element 2, but a plurality of second magnetoresistive elements 7 are provided. A plurality of second magnetoresistive elements 7 may be arranged for one first magnetoresistive element 2. In this case, the first magnetization free layer 2a and each second magnetization free layer 7a are magnetically coupled, and the magnetization 2e of the first magnetization free layer 2a and each second magnetization free layer 7a. Are magnetically coupled to the magnetization 7e. FIG. 15 shows a magnetoresistive effect device 500 according to the fifth embodiment in which one second magnetoresistive effect element 7 in the first embodiment is replaced with a plurality of second magnetoresistive effect elements 7. FIG. 16 is a schematic diagram of a circuit including the magnetoresistive effect device 500 of the fifth embodiment. In the magnetoresistive effect device 500, the first magnetoresistive effect element 2 and the plurality of second magnetoresistive effect elements 7 are electrically independent, and the plurality of second magnetoresistive effect elements 7 are electrically Connected in parallel.

  The magnetoresistive effect device 500 includes a plurality of second magnetoresistive effect elements 7, and the first magnetization free layer 2 a and the second magnetization free layer 7 a of each of the plurality of second magnetoresistive effect elements 7 are included. Since they are magnetically coupled, the respective second magnetoresistive effect elements 7 are electrically connected to each other, and the outputs from the respective second magnetoresistive effect elements 7 are summed up, resulting in higher oscillation. Output can be obtained.

  A magnetoresistive effect device 500 of the fifth embodiment is obtained by replacing one second magnetoresistive effect element 7 in the first embodiment with a plurality of second magnetoresistive effect elements 7. One second magnetoresistive element 7 in the fourth embodiment may be replaced with a plurality of second magnetoresistive elements 7. In addition, the second magnetoresistive elements 7 may be electrically connected in parallel or in series.

DESCRIPTION OF SYMBOLS 1 1st upper electrode 2 1st magnetoresistive effect element 2a 1st magnetization free layer 2b 1st spacer layer 2c 1st magnetization fixed layer 2d 1st antiferromagnetic layer 2e 1st magnetization free layer Magnetization 2f Magnetization 2g of the first magnetization fixed layer Straight line 3 parallel to the magnetization direction of the first magnetization fixed layer Magnetic field application mechanism 3a External magnetic field 3b Straight line 4 parallel to the direction of the external magnetic field 4 First lower electrode 5 Insulator 6 Second upper electrode 7 Second magnetoresistance effect element 7a Second magnetization free layer 7b Second spacer layer 7c Second magnetization fixed layer 7d Second antiferromagnetic layer 7e Magnetization of second magnetization free layer 7f Magnetization of the second magnetization fixed layer 7g Straight line 8 parallel to the magnetization direction of the second magnetization fixed layer 8 Second lower electrode 9 First input terminal 10 Bias tee 11 Output terminal 12 Second input terminal 13 Second 1 magnetic field applying mechanism 13a first external magnetic field 13b first Straight line 14 parallel to the direction of the external magnetic field of the second magnetic field applying mechanism 14a Second external magnetic field 14b Straight line 15 parallel to the direction of the second external magnetic field 15 Upper electrode 16 Nonmagnetic conductive buffer layer 17 Lower electrode 18 Input terminal 100 , 200, 300, 400, 500 Magnetoresistive device

Claims (3)

1st magnetoresistive effect element which has the 1st magnetization free layer, the 1st magnetization fixed layer, and the 1st spacer layer arranged between the 1st magnetization free layer and the 1st magnetization fixed layer When,
A second magnetoresistive element having a second magnetization free layer, a second magnetization fixed layer, and a second spacer layer disposed between the second magnetization free layer and the second magnetization fixed layer When,
A magnetic field application mechanism for applying an external magnetic field to the first magnetization free layer and the second magnetization free layer,
The first magnetization free layer and the second magnetization free layer are magnetically coupled;
Furthermore, the angle between the straight line parallel to the magnetization direction of the first magnetization fixed layer and the straight line parallel to the direction of the external magnetic field applied to the first magnetization free layer is greater than that of the second magnetization fixed layer. The angle formed by a straight line parallel to the magnetization direction and a straight line parallel to the direction of the external magnetic field applied to the second magnetization free layer is large,
A current having a current density equal to or higher than an oscillation threshold current density is applied to the first magnetoresistive element ,
The magnetoresistive effect device, wherein the first magnetoresistive effect element and the second magnetoresistive effect element are electrically connected in parallel . 1st magnetoresistive effect element which has the 1st magnetization free layer, the 1st magnetization fixed layer, and the 1st spacer layer arranged between the 1st magnetization free layer and the 1st magnetization fixed layer When,
A second magnetoresistive element having a second magnetization free layer, a second magnetization fixed layer, and a second spacer layer disposed between the second magnetization free layer and the second magnetization fixed layer When,
A magnetic field application mechanism for applying an external magnetic field to the first magnetization free layer and the second magnetization free layer,
The first magnetization free layer and the second magnetization free layer are magnetically coupled;
Furthermore, the angle between the straight line parallel to the magnetization direction of the first magnetization fixed layer and the straight line parallel to the direction of the external magnetic field applied to the first magnetization free layer is greater than that of the second magnetization fixed layer. The angle formed by a straight line parallel to the magnetization direction and a straight line parallel to the direction of the external magnetic field applied to the second magnetization free layer is large,
A current having a current density equal to or higher than an oscillation threshold current density is applied to the first magnetoresistive element ,
The magnetoresistive effect device, wherein the first magnetoresistive effect element and the second magnetoresistive effect element are electrically connected in series . 1st magnetoresistive effect element which has the 1st magnetization free layer, the 1st magnetization fixed layer, and the 1st spacer layer arranged between the 1st magnetization free layer and the 1st magnetization fixed layer When,
Second magnetization free layer, a plurality of second magnetoresistive having a second spacer layer disposed between the second magnetization pinned layer and the second magnetization free layer and the second magnetization pinned layer An effect element;
A magnetic field application mechanism for applying an external magnetic field to the first magnetization free layer and the second magnetization free layer,
Wherein the first magnetization free layer and the second magnetization free layer of each of the plurality of second magnetoresistive element are magnetically coupled,
Furthermore, the angle between the straight line parallel to the magnetization direction of the first magnetization fixed layer and the straight line parallel to the direction of the external magnetic field applied to the first magnetization free layer is greater than that of the second magnetization fixed layer. The angle formed by a straight line parallel to the magnetization direction and a straight line parallel to the direction of the external magnetic field applied to the second magnetization free layer is large,
A magnetoresistive effect device, wherein a current having a current density equal to or higher than an oscillation threshold current density is applied to the first magnetoresistive effect element.

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