JP4593300B2 - Manufacturing method and manufacturing apparatus for oxide superconducting wire - Google Patents

Description

  The present invention relates to a method and an apparatus for manufacturing an oxide superconducting wire.

  The Y-based oxide superconductor discovered in recent years is known to be effective for application in a magnetic field at a liquid nitrogen temperature (77 K) because the pinning force is sustained to a high temperature. Currently, there are various problems to be solved in order to use this type of oxide superconductor as a practical superconductor. One of the problems is that the critical current density of the oxide superconductor decreases in a strong magnetic field.

  The problem that the critical current density of the oxide superconductor decreases in the strong magnetic field is largely due to the presence of electrical anisotropy in the oxide superconductor crystal itself. It is known that the body can easily flow electricity in the a-axis direction and the b-axis direction of its crystal axis, but hardly flows electricity in the c-axis direction. From this point of view, in order to form an oxide superconductor on a substrate and use it as a superconductor, an oxide superconductor with a good crystal orientation is formed on the substrate, It is necessary to orient the a-axis or b-axis of the oxide superconductor crystal in the direction in which electricity is to flow and to orient the c-axis of the oxide superconductor in the other direction.

  By the way, in order to use an oxide superconductor as a conductor, it is necessary to form a superconducting layer with good crystal orientation on a long substrate such as a tape. However, when a superconducting layer is directly formed on a substrate such as a metal tape, the metal tape itself is polycrystalline and its crystal structure is significantly different from that of an oxide superconductor. It is not possible. Moreover, since a diffusion reaction occurs between the metal tape and the superconducting layer due to the heat treatment performed when forming the superconducting layer, there is a problem that the crystal structure of the superconducting layer is destroyed and the superconducting characteristics are deteriorated.

  Therefore, the present inventors have made a polycrystalline intermediate thin film such as yttria-stabilized zirconia (YSZ) on a long tape-like substrate 1 made of a metal tape such as a Ni-base heat-resistant alloy hastelloy tape as shown in FIG. YBaCuO-based superconducting layer 3 having an excellent stability and having a critical temperature of about 90 K among oxide superconductors and being usable in liquid nitrogen (77 K). Various attempts have been made to produce an oxide superconducting wire 5 having excellent superconducting characteristics by forming (see, for example, Patent Documents 1 to 4).

  According to these prior arts, when a polycrystalline intermediate thin film is formed on a base material of a metal tape such as a Hastelloy tape by a sputtering apparatus, while irradiating an ion beam from an oblique direction of the base material film formation surface simultaneously with sputtering. A polycrystalline intermediate thin film having excellent crystal orientation can be formed by an ion beam assist method (hereinafter referred to as IBAD method) for forming a polycrystalline intermediate thin film. According to this IBAD method, the grain boundary inclination angle formed by the a-axis or b-axis of each crystal lattice of a large number of crystal grains forming the polycrystalline intermediate thin film can be made to be 30 degrees or less, and the crystal orientation is excellent. A polycrystalline intermediate thin film can be formed. Furthermore, if a YBaCuO-based superconducting layer is formed on the intermediate thin film having excellent orientation by a film forming method such as sputtering or physical vapor deposition such as laser deposition, the crystal orientation of the superconducting layer is also improved. As a result, an oxide superconducting wire having a high critical current density can be formed.

  FIG. 5 shows an example of a conventional laser vapor deposition apparatus. This laser vapor deposition apparatus has a processing vessel 10 that is configured to be evacuated inside, and a polycrystalline tape is formed on the surface of a long tape-like substrate on the lower side of the vapor deposition chamber 10a inside the processing vessel 10. A base material 11 (hereinafter referred to as a tape base material) for forming a superconducting layer formed by forming a thin film is provided, and an oxide superconductor or an oxide superconductor is approximated above the tape base material 11. While a target 12 having a composition is provided, a laser light emitting device 14 for generating a jet of particles (hereinafter referred to as plume) 13 by irradiating the surface of the target 12 with laser light 25 is provided outside the processing vessel 10. Is provided.

The processing vessel 10 is connected to a vacuum exhaust device (not shown) through an exhaust hole 10b so that the inside can be evacuated. The target 12 is plate-shaped, and is supported by a target holder 12a so that the lower surface of the target 12 faces the upper surface of the tape base 11 in parallel. Further, a slit plate 15 having a window hole 15a is disposed between the tape base material 11 and the target 12, and only particles that have passed through the window hole 15a among particles moving from the target 12 toward the tape base material 11 are provided. Can be selectively deposited on the tape substrate 11. The width of the slit plate 15 (the width of the slit plate 15 along the width direction of the tape-shaped substrate 1) is such that the tape substrate 11 can be hidden from the target 12 side as shown in FIG. It is formed larger than the width of the material 11. The horizontal width of the window hole 15a (the width of the window hole 15a along the width direction of the tape-shaped base material 1) is about the same as or slightly wider than the width of the base material 1, and the vertical width W ₁ (of the tape base material 11). The width of the window hole 15a along the length direction) is about 20 to 80 mm.

For example, when the vertical width W ₁ is 35 mm, the slit plate 15 having such a window hole 15a has a window in which the center line G of the plume 13 moving from the target 12 toward the tape base 11 is a window as shown in FIG. as passing through the center of the hole 15a, that is, the distance _{L 1} is 17.5mm about the end face 16 of the upstream side with respect to the moving direction of the tape base 11 of the center line G and window hole 15 of the plume 13, and plume 13 between the tape base 11 and the target 12 so that the distance L ₂ between the end surface 17 on the downstream side is about 17.5mm and the center line G with respect to the moving direction of the tape base 11 of the window hole 15a of the Arranged.

  On the lower side of the tape base material 11, a feeding device 18 and a winding device 19 are provided separately from each other, and the tape base material 11 can be sent out from the feeding device 18 and taken up by the winding device 19. The tape base 11 can be moved horizontally below the target 12. A heater 20 for heating the tape substrate 11 is provided between the feeding device 18 and the winding device 19. A first reflecting mirror 21, a condenser lens 22, and a second reflecting mirror 23 are provided between the laser light emitting device 14 and the processing container 10, and the laser light 25 generated by the laser light emitting device 14 is supplied to the processing container 10. The target 12 can be condensed and irradiated through a transparent window 24 attached to the side wall of the target. Further, in the conventional laser vapor deposition apparatus, when particles are deposited on the tape base material 11, a constant output is supplied to the heater 20 in order to keep the surface temperature of the tape base material 11 constant. Or a thermocouple (TC) 20a for measuring the temperature of the gap A between the heater 20 and the tape substrate 11 is disposed in the gap A, and a thermocouple (T.C. C.) A control unit (not shown) is provided that changes the output to be applied to the heater 20 so that the temperature of the gap A is constant based on the measurement value measured at 20a.

  In order to form a superconducting layer on the tape substrate 11 using the laser vapor deposition apparatus having the above-described configuration, the laser light 25 is emitted from the laser light-emitting device 14, and the first reflecting mirror 21, the condensing lens 22, and the second reflecting mirror are emitted. The target 12 is irradiated with a laser beam 25 through a transparent window 24 and a transparent window 24. On the other hand, the tape base material 11 on which the polycrystalline intermediate thin film 2 is formed is sequentially sent out from the feeding device 18 at a predetermined speed with the surface on the polycrystalline intermediate thin film side facing up, and wound up on the winding device 19. The tape base 11 is heated by moving the lower part of the target 12 horizontally and operating the heater 20. At the time of heating, a constant output is supplied to the heater 20 or the temperature of the gap A is measured by the thermocouple 20a, and the output of the heater 20 is changed by the controller based on the measured value. To do.

In this way, the surface of the target 12 irradiated with the laser beam 25 is removed or evaporated, and the constituent particles are knocked out, and among the particles, the particles that have passed through the window holes 15 a are many of the tape base material 11. At the same time as being deposited on the crystal intermediate thin film 2, it is heat-treated by the heater 20. By sequentially depositing particles on the upper surface of the tape base 11 by the above operation, a superconducting layer made of an oxide superconductor such as Y ₁ Ba ₂ Cu ₃ O _x (YBCO) is formed on the tape base 11. The oxide superconducting wire 5 as shown in FIG. 4 can be obtained.

  Since a superconducting current flows in a copper-oxygen plane in a copper oxide superconductor such as YBCO, it is necessary to form a c-axis oriented film so that the copper-oxygen plane is connected. In order to form a c-axis oriented YBCO layer, the surface temperature of the tape substrate during film formation needs to be about 800 ° C. If the temperature is lower, a-axis oriented YBCO is formed, and the path of the superconducting current is interrupted. Also, if the surface temperature of the tape base material during film formation becomes too high, the YBCO superconductor itself cannot be formed.

In order to control the tape substrate surface temperature during film formation in the conventional method described above, as shown in FIG. 7A, a hot plate 26 having a curved surface 26a bulging toward the window hole 15a of the slit plate 15. Is placed adjacent to the slit plate 15, the tape substrate 11 is moved along the curved surface 26 a, and the heating temperature is adjusted by a heater built in the hot plate 26, thereby forming the tape substrate at the time of film formation. The surface temperature can be accurately controlled.
Japanese Patent No. 2614948 Japanese Patent No. 2721595 Japanese Patent No. 3251034 Japanese Patent No. 2996568

  However, as shown in FIG. 7A, when the film is formed by bringing the tape substrate 11 into contact with the curved surface 26a of the hot plate 26, the surface temperature of the tape substrate 11 is as shown in FIG. It has been found that both sides of the curved surface 26a are hotter than the center. That is, as shown in FIG. 7A, the slit plate 15 is provided on the curved surface 26a side of the hot plate 26 so that the vapor deposition particles do not adhere to the portion where the tape substrate 11 is not heated. 15 a is located at the center of the hot plate 26, and both sides of the hot plate 26 are covered with the slit plate 15. Since both sides of the hot plate 26 are covered with the slit plate 15, the temperature is kept by the slit plate 15, and the surface temperature of the tape base 11 is as shown in FIG. 7B. The direction becomes higher by about 30 to 40 ° C. than the central part. Therefore, even if a favorable film can be formed on the tape base material 11 by the window hole 15a of the slit plate 15, it passes through the portion where the temperature becomes high, so that the interface between the polycrystalline intermediate thin film and the superconducting layer made of YBCO. There is a problem that the reaction layer is easily formed, and the superconducting properties of the obtained oxide superconducting wire are deteriorated.

  This invention is made | formed in view of the said situation, and it aims at provision of the manufacturing method and manufacturing apparatus which can manufacture stably the oxide superconducting wire excellent in the superconducting characteristic.

In order to achieve the above object, the present invention provides an oxide superconductor provided in a vapor deposition chamber or a target having an approximate composition as that of an oxide superconductor by irradiating a laser beam with particles generated from the target, and forming a window on a slit plate. through holes, a method of manufacturing an oxide superconducting wire to form the oxide superconducting layer by sequentially depositing onto a tape base material in the moving while being heated along a heat plate positioned adjacent to said slit plate, said As the tape base material for forming the oxide superconducting layer, a tape base material provided with an in-plane oriented polycrystalline intermediate thin film is used, and the hot plate has a curved surface that gradually increases in thickness from both ends to the center. The curved surface has a central portion that bulges toward the window hole of the slit plate, and the central portion of the curved surface is desired at the central portion in the longitudinal direction of the window hole of the slit plate. Not both of the curved surfaces Are disposed in the vapor deposition processing chamber so as to be adjacent to the edge of the slit plate located at the peripheral edges at both ends in the length direction of the rectangular window hole, and the temperature of the curved surface is heated to an appropriate vapor deposition temperature as the hot plate. A heater built-in type is used, and the slit plate has a rectangular window hole in the center thereof, and the slit plate includes a peripheral portion at both ends in the length direction of the window hole of the slit plate. A cooling means is provided extending from both ends of the hot plate to the outside of both ends of the window hole in the length direction , and a plume that is a jet of particles generated from the target is passed through the window hole to when particles deposited against the tape base material to move along the curved surface of the heating plate, with respect to the hot plate whose temperature was controlled deposition suitable temperature the curved surface, both end sides of the hot plate covered by the window hole periphery the cooling hand local Atsushi Nobori It provides a method of manufacturing an oxide superconducting wire, which comprises forming the oxide superconducting layer while maintaining the surface temperature distribution of the tape base material uniformly on the polycrystalline intermediate thin film while preventing the.

In the method for manufacturing an oxide superconducting wire according to the present invention, the cooling means includes both peripheral edges at both ends in the length direction of the window hole of the slit plate and both ends in the length direction of the window hole of the slit plate from this peripheral edge. It is preferable that the cooling device flows a cooling medium through a cooling pipe line extending from both end positions of the hot plate to the outside toward the outside.

The present invention also provides a processing vessel having a transparent window into which laser light is incident, an oxide superconductor provided in the vapor deposition chamber of the processing vessel or a target having an approximate composition with the oxide superconductor, and the vapor deposition chamber. A hot plate for heating the tape base material provided facing the target, a feeding device and a winding device for moving the tape base material along the longitudinal direction on the hot plate, the hot plate and the hot plate An oxide superconductor manufacturing apparatus comprising: a slit plate provided so that a window hole is positioned between targets; and a laser light emitting device that irradiates laser light toward the target through the transparent window , As the tape base material for forming the oxide superconducting layer, a tape base material provided with an in-plane oriented polycrystalline intermediate thin film is applied, and the thickness of the hot plate is gradually increased from both end sides toward the center. One side of the curved surface And having the center of the curved surface bulge toward the window hole of the slit plate, and the center of the curved surface is desired at the center in the length direction of the window hole of the slit plate, Both sides of the curved surface are disposed in the vapor deposition chamber so as to be adjacent to the edge of the slit plate located at the peripheral edges of the rectangular window hole in the length direction, and the hot plate vaporizes the temperature of the curved surface. The heater has a built-in heater that heats to an appropriate temperature, and the slit plate has a rectangular window hole at the center thereof, and includes a peripheral edge at both ends in the length direction of the window hole of the slit plate. A cooling means is provided extending from both ends of the hot plate to the outside of both ends of the slit plate in the longitudinal direction, and passes through the plume, which is a jet of particles generated from the target. And move along the curved surface of the hot plate. The against the tape base material and configuration capable of particle deposition, the curved surface to the hot plate whose temperature was controlled deposition suitable temperature, the cooling local Atsushi Nobori at both ends of the hot plate covered by the window hole periphery to providing an apparatus for producing an oxide superconductor, characterized in that the oxide superconductor layer while maintaining the surface temperature distribution of the tape base material uniformly be formed on the polycrystalline intermediate thin film while preventing the unit.

In the apparatus for manufacturing an oxide superconductor according to the present invention, in the apparatus for manufacturing an oxide superconductor according to the present invention, the cooling means includes the peripheral portion including the peripheral portions at both ends in the length direction of the window hole of the slit plate. It is preferable that the cooling device flows a cooling medium through a cooling pipe line extending from a position on both ends of the heat plate to the outside thereof from both ends outside in the length direction of the window hole of the slit plate.

According to the present invention, the cooling means is provided at the periphery of the window hole of the slit plate, and has a curved surface that gradually increases in thickness from both ends toward the center, and the center of the curved surface is desired at the center of the window hole. The deposited heat plate is placed, and the deposition of particles from the plume generated from the target is performed through the window hole to place the oxide superconducting layer on the in-plane oriented polycrystalline thin film on the tape substrate on the hot plate. When forming the oxide superconducting layer while maintaining the surface temperature distribution of the tape substrate uniformly by preventing local temperature rise on both ends of the hot plate covered by the peripheral edge of the slit plate , Since the oxide superconducting layer can be formed with a uniform surface temperature distribution on the tape substrate, the superconducting properties can be prevented from deteriorating due to local heating of the hot plate for heating the tape substrate. oxides than having a uniform oxide superconductor layer is excellent It is possible to produce a wire material.
A cooling device for supplying a cooling medium to a cooling pipe as a cooling means, and extending the cooling pipe from the peripheral edge at both ends in the length direction of the slit plate to the outside of both ends in the length direction of the slit plate. The temperature of the tape substrate surface that moves on the hot plate is prevented by increasing the temperature of the hot plate at both ends of the hot plate and covered by the slit plate. There is an effect that heating can be performed uniformly without increasing the height on the side compared to the center side.

Embodiments of the present invention will be described below with reference to the drawings.
1 to 3 show a laser vapor deposition apparatus which is an embodiment of an apparatus for manufacturing an oxide superconductor according to the present invention, FIG. 1 is a configuration diagram of this laser vapor deposition apparatus, and FIG. FIG. 3 is a plan view of the slit plate 27 used in the same laser vapor deposition apparatus. In the present embodiment, as shown in FIG. 4, a laser deposition method (pulse laser deposition (PLD)) is applied to a tape substrate 11 in which a polycrystalline intermediate thin film 2 is formed on a metal substrate 1 by an IBAD method. In this example, the superconducting layer 3 made of an oxide superconductor is formed by the above method to produce a long tape-shaped oxide superconducting wire 5.

  Examples of the constituent material of the base material 1 used for the tape base material 11 include a long metal tape appropriately selected from various metal materials such as stainless steel or nickel alloys such as Hastelloy and Inconel. The base material 1 has a thickness of 0.01 to 0.5 mm, preferably 0.02 to 0.15 mm. When the thickness of the substrate 1 is 0.5 mm or more, it is thicker than the film thickness of the oxide superconductor thin film 3 described later, and the critical current density per overall (total cross-sectional area of the oxide superconductor) is reduced. . On the other hand, if the thickness of the base material 1 is less than 0.01 mm, the strength of the base material 1 is remarkably lowered, and the reinforcing effect of the oxide superconducting conductor 4 is lost.

The polycrystalline intermediate thin film 2 formed on the substrate 1 is formed by joining and integrating a large number of fine crystal grains in which crystals having a cubic crystal structure are gathered through a crystal grain boundary. The c-axis of the crystal axis of each crystal grain is oriented substantially perpendicular to the upper surface (film formation surface) of the substrate 1, and the a-axis and the b-axis of each crystal grain are in the same direction. Is oriented in-plane. The thickness of the polycrystalline intermediate thin film 2 is 0.1 to 1.0 μm. Even if the thickness of the polycrystalline intermediate thin film 2 exceeds 1.0 μm, an increase in the effect can no longer be expected, which is disadvantageous economically. On the other hand, if the thickness of the polycrystalline intermediate thin film 2 is less than 0.1 μm, the superconducting layer 3 may not be sufficiently supported because it is too thin. As a constituent material of the polycrystalline intermediate thin film 2, MgO, SrTiO ₃ or the like can be used in addition to Gd ₂ Zr ₂ O ₇ , CeO ₂ , YSZ.

Superconducting layer 3 formed of an oxide _{superconductor, Y 1 Ba 2 Cu 3 O} x, Y 2 Ba 4 Cu 8 O x, Y 3 Ba 3 Cu 6 O x, Gd 1 Ba 2 Cu 3 O x, Yb 1 Ba ₂ Cu ₃ O _x , Ho ₁ Ba ₂ Cu ₃ O _x , (Bi, Pb) ₂ Ca ₂ Sr ₂ Cu ₃ O _x , (Bi, Pb) ₂ Ca ₂ Sr ₃ Cu ₄ O _x , or Consisting of a supercritical oxide superconductor represented by the composition of Tl ₂ Ba ₂ Ca ₂ Cu ₃ O _x , Tl ₁ Ba ₂ Ca ₂ Cu ₃ O _x , Tl ₁ Ba ₂ Ca ₃ Cu ₄ O _x It is. The thickness of this superconducting layer 3 is about 0.5 to 5 μm and has a uniform thickness. In addition, the film quality of the superconducting layer 3 is uniform, and the c-axis, a-axis, and b-axis of the crystal of the superconducting layer 3 are epitaxially grown and crystallized so as to match the crystal of the polycrystalline intermediate thin film 2. The orientation is excellent.

  The laser vapor deposition apparatus of the present embodiment includes a processing container 10 having a transparent window 24 into which laser light 25 is incident and an internal vapor deposition processing chamber 10a configured to be evacuated, and the vapor deposition processing chamber 10a of the processing container 10. A target 12 having a composition similar to that of the oxide superconductor or the oxide superconductor provided therein, a hot plate 28 for heating the tape base 11 provided in the vapor deposition chamber 10a so as to face the target 12, A feeding device 18 and a winding device 19 for moving the tape base material 11 along its longitudinal direction on the hot plate 28, and a slit plate provided so that a window hole 27 a is located between the hot plate 28 and the target 12. 27 and a laser light emitting device 14 that irradiates the laser beam 25 toward the target 12 through the transparent window 24, and the local area of the hot plate 28 that is covered with the window hole peripheral part of the slit plate 27. It has a configuration in which a cooling pipe 29 of the cooling means for maintaining the surface temperature distribution of the tape base material 11 uniformly prevent the Atsushi Nobori.

The processing vessel 10 is connected to a vacuum exhaust device (not shown) through an exhaust hole 10b so that the inside can be evacuated. In the transparent window 24 provided in the processing container 10, the laser light 25 from the laser light emitting device 14 is incident through the first reflecting mirror 21, the condensing lens 22, and the second reflecting mirror 23, and the inside of the vapor deposition processing chamber 10a. It is possible to irradiate the target 12 disposed on the surface. As this laser light emitting device 22, an excimer laser such as Ar—F (193 nm) and Kr—F (248 nm), a YAG laser, etc., as long as it can generate laser light 25 that can knock out constituent particles from the target 12. Any one such as a CO ₂ laser may be used. The irradiation output of the laser beam 5 can be adjusted by adjusting the output of an amplifier (not shown) that supplies power to the laser light emitting device 14. The irradiation frequency of the laser beam 25 indicates the number of laser pulses intermittently oscillated per second, and this adjustment supplies power to the laser light-emitting device 14 intermittently at a constant frequency. Alternatively, adjustment can be made by providing a mechanical shutter such as a rotating sector somewhere in the path through which the laser beam 25 passes and operating this mechanical shutter at a constant frequency.

The target 12 has a composition equivalent to or close to that of the superconducting layer 3 to be formed, or a plate body such as a sintered body of a complex oxide or an oxide superconductor containing a large amount of components that easily escape during film formation. It is made up of. Accordingly, the target 12 of the oxide superconductor is Y ₁ Ba ₂ Cu ₃ O _x , Y ₂ Ba ₄ Cu ₈ O _x , Y ₃ Ba ₃ Cu ₆ O _x , Gd ₁ Ba ₂ Cu ₃ O _x , Yb ₁ Ba. ₂ Cu ₃ O _x , Ho ₁ Ba ₂ Cu ₃ O _x , (Bi, Pb) ₂ Ca ₂ Sr ₂ Cu ₃ O _x , (Bi, Pb) ₂ Ca ₂ Sr ₃ Cu ₄ O _x , or The same composition as the superconducting layer 3 having a high critical temperature represented by the composition of Tl ₂ Ba ₂ Ca ₂ Cu ₃ O _x , Tl ₁ Ba ₂ Ca ₂ Cu ₃ O _x , Tl ₁ Ba ₂ Ca ₃ Cu ₄ O _x It is preferable to use a composition having an approximate composition. This target 12 is plate-shaped, and is supported by a target holder 12a so that the lower surface of the target 12 faces the upper surface of the tape base 11 in parallel.

  The hot plate 28 is provided with a curved surface 28a that gradually increases in thickness from both ends toward the center, and is deposited so that the central portion of the curved surface 28a bulges toward the window hole 27a of the slit plate 27. It arrange | positions in the processing chamber 10a. The hot plate 28 has a built-in heater so that the curved surface 28a that the tape base material 11 contacts while moving can be heated and maintained at an appropriate vapor deposition temperature (about 800 ° C.). This temperature adjustment can be performed by a method in which a temperature sensor such as a thermocouple is built in the hot plate 28 and the output of the heater is controlled so that the surface temperature of the curved surface 28a becomes an appropriate deposition temperature.

  As shown in FIG. 3, the slit plate 27 has a rectangular plate shape made of a stainless steel plate or the like. A window hole 27a is formed in the center of the slit plate 27, and a cooling pipe 29 is provided in the peripheral portion thereof. . In the present embodiment, a cooling pipe 29 is provided on each side in the longitudinal direction of a rectangular window hole 27a. The cooling pipe 29 is connected to a cooling device (not shown), and can circulate a cooling medium supplied from the cooling device, thereby cooling the peripheral portion of the window hole 27a. As the cooling medium, a liquid such as water or a gas such as an inert gas can be used.

In order to form the superconducting layer 3 of Y ₁ Ba ₂ Cu ₃ O _x on the tape substrate 11 using the laser vapor deposition apparatus shown in FIG. 1, the tape substrate 11 on which the polycrystalline intermediate thin film 2 is formed is used. This polycrystalline intermediate thin film 2 side is placed on the curved surface 28a of the hot plate 28, and a plate-like target 12 made of Y ₁ Ba ₂ Cu ₃ O _{X is used} as the target 12 of the oxide superconductor in the target holder 12a. Attach and depressurize the vapor deposition chamber 10a with a vacuum exhaust device. Here, if necessary, oxygen gas may be introduced into the vapor deposition chamber 10a to make the vapor deposition chamber 10a an oxygen atmosphere.

  A heater built in the hot plate 28 is operated so that the surface temperature of the tape base material 11 on the hot plate 28 becomes an appropriate deposition temperature, and a cooling medium is supplied to the cooling pipe 29 provided in the slit plate 27. Then, the peripheral edge of the window hole 27a is cooled. Next, while feeding the tape substrate 11 from the delivery device 18, the laser light 25 is generated from the laser light emitting device 14, the laser light 25 is introduced into the vapor deposition processing chamber 10 a through the transparent window 24, and the target 12 is irradiated.

  FIG. 2A shows a state when the superconducting layer 3 is formed. When the target 12 is irradiated with the laser beam 25, the constituent particles of the target 12 are knocked out or evaporated, and the ejected plume 13 flows through the window hole 27a of the slit plate 27, and the tape base material 11 on the hot plate 28. A superconducting layer 3 is formed by depositing on the polycrystalline intermediate thin film 2 on the surface. While moving the tape substrate 11 along the longitudinal direction on the hot plate 28 at a predetermined speed, laser deposition is performed to sequentially deposit the superconducting layer 3 made of an oxide superconductor on the tape substrate 11, thereby superconducting layer 3. The long oxide superconducting wire 5 can be manufactured by continuing the vapor deposition process in which the oxide superconducting wire having been formed is wound around the winding device 19.

  In the present embodiment, cooling pipes 29 are provided on both sides of the window hole 27a of the slit plate 27, and a cooling medium is passed through the cooling pipe 29 to cool both sides of the window hole 27a. It is possible to prevent the both side portions of the broken heat plate 27 from being locally heated. In the present embodiment, the cooling pipe 29 is provided on both sides of the window hole 27a in the window hole peripheral part of the slit plate 27, and cooling is performed. It can be set as the structure which cools the whole region or only one part of a window hole peripheral part. Hereinafter, a portion to be cooled by providing the cooling pipe 29 including not only cooling both sides of the window hole 27a but also the entire periphery is referred to as “periphery of the window hole 27a”.

  Thus, by cooling the peripheral edge of the window hole 27a, the region covered with the peripheral edge of the window hole 27a in the curved surface 28a of the hot plate 28 is not locally heated. The surface temperature distribution of the tape base material moving on the surface 28 becomes uniform. FIG. 2B is a graph illustrating the tape substrate surface temperature distribution measured in a state where the peripheral edge of the window hole 27a is cooled, and shows a case where the peripheral edge of the window hole 27a is not cooled. Compared with the graph of (b), the surface of the tape base material of this embodiment shown in FIG. 2 (b) has no local temperature rise, and the region corresponding to the window hole 27a has a uniform temperature distribution.

  In the state where the window hole peripheral portion of the slit plate is not cooled as shown in FIG. 7A, the both sides of the curved surface 26a are higher by about 30 to 40 ° C. than the central portion as shown in FIG. 7B. The temperature rises. Therefore, a reaction layer is likely to be formed at the interface between the polycrystalline intermediate thin film 2 and the superconducting layer 3 made of an oxide superconductor such as a YBaCuO system, and the superconducting characteristics of the resulting oxide superconducting wire are likely to deteriorate. On the other hand, in this embodiment, as shown in FIG. 2A, the peripheral portion of the window hole 27a is cooled, so that the region covered by the peripheral portion of the window hole 27a in the curved surface 28a of the hot plate 28 is provided. However, the surface temperature distribution of the tape base material moving on the hot plate 28 becomes uniform. As a result, after the superconducting layer 3 is formed on the tape substrate 11, the superconducting layer 3 is not subjected to excessive heating, and a reaction layer is not formed at the interface between the polycrystalline intermediate thin film 2 and the superconducting layer 3. It is possible to produce an oxide superconducting wire having a uniform superconducting layer excellent in.

[Example]
A first polycrystalline intermediate thin film made of Gd ₂ Zr ₂ O _{7 having a} film thickness of about 1 μm and an orientation of 10 degrees is formed on a Hastelloy tape base material by an IBAD method, and PLD is formed on the first polycrystalline intermediate thin film. A tape base material having a length of 100 m on which a second polycrystalline intermediate thin film made of CeO _{2 having an} orientation of 5 degrees was formed by the above method. The tape base material by the polycrystalline intermediate thin side up and placed on a hot plate of the laser deposition apparatus shown in FIG. _{1, Y 1 Ba 2 Cu 3} O X system support holder disc-shaped target as the target The vapor deposition chamber was decompressed with a vacuum exhaust device. While feeding the tape base material from the delivery device at 1.0 m / h, laser light was generated from the laser light emitting device and the target was irradiated with the laser light. The intensity of the laser beam was 20 W, and the irradiation frequency was 100 Hz. Cooling water flows through cooling pipes provided on both sides of the slit hole in the slit plate, and a heater and cooling built in the hot plate so that the surface temperature of the tape substrate passing on the curved surface of the hot plate is about 800 ° C. Water was controlled on / off. When the surface temperature distribution of the tape base material in contact with the curved surface of the hot plate in this state was measured, as shown in FIG. 2B, the heating region was uniform at about 800 ° C., and no local temperature increase was observed. Under these conditions, a superconducting layer was formed on the tape substrate to produce a long oxide superconducting wire. In the obtained oxide superconducting wire, the thickness of the superconducting layer was about 0.5 μm, and the critical current density (Jc) value of 0.1 m length was 1.9 MA / cm ² .

[Comparative example]
A superconducting layer was formed on the tape base material in the same manner as in the example except that the cooling water did not flow through the cooling pipe line of the slit plate and the periphery of the window hole was not cooled.
In this state, when the surface temperature distribution of the tape base material in contact with the curved surface of the hot plate was measured, as shown in FIG. 7B, the central portion was about 800 ° C., but both sides were 30 to 40 ° C. The temperature was rising. Under these conditions, a superconducting layer was formed on the tape substrate to produce a long oxide superconducting wire. The obtained oxide superconducting wire has a superconducting layer thickness of about 0.5 μm, a critical current density (Jc) value of 0.1 m length is 1.6 MA / cm ² , and is obtained in the above example. The critical current density was lower than that.

It is a block diagram of the laser vapor deposition apparatus which is one Embodiment of the manufacturing method of the oxide superconducting wire of this invention. It is a graph which shows the principal part enlarged view and tape surface temperature distribution of a laser vapor deposition apparatus. It is a top view of the slit board used for the same laser vapor deposition apparatus. It is a perspective view of an oxide superconducting wire. It is a block diagram of the conventional laser vapor deposition apparatus. It is a principal part enlarged view of the conventional laser vapor deposition apparatus. It is a graph which shows the principal part enlarged view and tape surface temperature distribution of the conventional laser vapor deposition apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base material, 2 ... Polycrystalline intermediate | middle thin film, 3 ... Superconducting layer, 5 ... Oxide superconducting wire, 10 ... Processing container, 10a ... Deposition processing chamber, 10b ... Exhaust hole, 11 ... Tape base material, 12 ... Target, 12a ... target holder, 13 ... plume, 14 ... laser light emitting device, 18 ... delivery device, 19 ... winding device, 21 ... first reflecting mirror, 22 ... condensing lens, 23 ... second reflecting mirror, 24 ... transparent window 25 ... laser beam, 26, 28 ... hot plate, 26a, 28a ... curved surface, 27 ... slit plate, 27a window hole, 29 ... cooling conduit.

Claims (4)

The oxide superconductor provided in the vapor deposition chamber or a target having an approximate composition with the oxide superconductor is irradiated with laser light and the particles generated from the target are placed adjacent to the slit plate through the window hole of the slit plate. a method of manufacturing an oxide superconducting wire by sequentially depositing onto a tape base material in the moving while being heated along a plate to form the oxide superconducting layer,
As a tape base material for forming the oxide superconducting layer, a tape base material provided with an in-plane oriented polycrystalline intermediate thin film,
The heat plate is shaped to have a curved surface on one surface side that gradually increases the thickness from both end sides toward the center, so that the central portion of the curved surface bulges toward the window hole of the slit plate, and The center portion of the curved surface is desired at the center portion in the length direction of the window hole of the slit plate, and both side portions of the curved surface are formed at the edge portions of the slit plate located at the peripheral edges at both ends in the length direction of the rectangular window hole. Arranged in the vapor deposition processing chamber so as to be adjacent, using a heater built-in type that heats the curved surface to an appropriate vapor deposition temperature as the hot plate,
The slit plate has a rectangular window hole in the center, both longitudinal ends outside of the slit plate window opening from the peripheral edge portion including the peripheral portion of the longitudinal opposite ends of the window holes of the slit plate Providing a cooling means extending from both ends of the hot plate to the outside thereof ,
When depositing particles by applying a plume, which is a jet of particles generated from the target, to the tape substrate that moves along the curved surface of the hot plate through the window hole, the curved surface is temperature controlled to an appropriate temperature for vapor deposition. the respect to the hot plate, an oxide superconducting layer while maintaining the surface temperature distribution of the tape base material uniformly while preventing by said cooling means local heating of both end sides of the hot plate covered by the window hole periphery It forms on the said polycrystal intermediate | middle thin film , The manufacturing method of the oxide superconducting wire characterized by the above-mentioned . The cooling means includes a peripheral edge at both ends in the length direction of the window hole of the slit plate, and extends from the peripheral edge to the outer ends at both ends in the length direction of the window hole of the slit plate from the positions on both ends of the hot plate. The method for producing an oxide superconducting wire according to claim 1, wherein the cooling device is a cooling device that causes a cooling medium to flow to a cooling pipe line extending to the point . A processing container having a transparent window into which laser light is incident, an oxide superconductor provided in the vapor deposition chamber of the processing container or a target having an approximate composition with the oxide superconductor, and facing the target in the vapor deposition chamber A heating plate for heating the tape substrate, a feeding device and a winding device for moving the tape substrate along the longitudinal direction on the heating plate, and a window between the heating plate and the target An oxide superconductor manufacturing apparatus comprising: a slit plate provided so that a hole is positioned; and a laser light emitting device that irradiates a laser beam toward the target through the transparent window ,
As the tape base material for forming the oxide superconducting layer, a tape base material provided with an in-plane oriented polycrystalline intermediate thin film is applied,
The heat plate is shaped to have a curved surface on one surface side that gradually increases the thickness from both end sides toward the center, so that the central portion of the curved surface bulges toward the window hole of the slit plate, and The center portion of the curved surface is desired at the center portion in the length direction of the window hole of the slit plate, and both side portions of the curved surface are formed at the edge portions of the slit plate located at the peripheral edges at both ends in the length direction of the rectangular window hole. Arranged in the vapor deposition processing chamber so as to be adjacent, the heating plate is a built-in heater that heats the temperature of the curved surface to an appropriate vapor deposition temperature,
The slit plate has a rectangular window hole in the center, both longitudinal ends outside of the slit plate window opening from the peripheral edge portion including the peripheral portion of the longitudinal opposite ends of the window holes of the slit plate A cooling means is provided extending from both ends of the hot plate to the outside thereof ,
The plume, which is a jet of particles generated from the target, passes through the window hole and is applied to the tape base material that moves along the curved surface of the hot plate, so that the particles can be deposited. to the control by said heating plate, the oxide superconducting layer while maintaining the surface temperature distribution of the tape base material uniformly while preventing by said cooling means local heating of both end sides of the hot plate covered by the window hole periphery Can be formed on the polycrystalline intermediate thin film . The cooling means includes a peripheral edge at both ends in the length direction of the window hole of the slit plate, and extends from the peripheral edge to the outer ends at both ends in the length direction of the window hole of the slit plate from the positions on both ends of the hot plate. 4. The apparatus for producing an oxide superconducting wire according to claim 3 , wherein the apparatus is a cooling device that causes a cooling medium to flow through a cooling pipe line extending up to .

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