SU819655A1

SU819655A1 - Method of measuring ferromagnetic resonance band width

Info

Publication number: SU819655A1
Application number: SU772446936A
Authority: SU
Inventors: Владимир Никитович Зинченко; Олег Викторович Огаренко; Галина Владимировна Шмелева
Original assignee: Предприятие П/Я Г-4126
Priority date: 1977-01-25
Filing date: 1977-01-25
Publication date: 1981-04-07

Description

(54) СПОСОБ ИЗМЕРЕНИЯ ШИРИНЫ ЛИНИИ ФЕРРОМАГНИТНОГО РЕЗОНАНСА(54) METHOD OF MEASURING THE WIDTH OF A LINE OF FERROMAGNETIC RESONANCE

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Изобретение относитс к радиоспектроскопии и может быть использовано при измерении параметров спектра магнитного резонанса , в частности, ширины линии (Д Н) при ферромагнитном резонансе (ФМР).The invention relates to radio spectroscopy and can be used to measure the parameters of the magnetic resonance spectrum, in particular, the line width (D N) in the case of ferromagnetic resonance (FMR).

Известны способы 1 измерени ЛН по изменению параметров полых электродинамических систем, содержащих исследуемые образцы, обусловленному влением ФМР.Methods 1 are known for measuring the LF by changing the parameters of hollow electrodynamic systems containing the test samples, due to the phenomenon of FMR.

В известных способах требуетс установка отсчетного уровн сигнала СВЧ с помощью аттенюатора, что существенно увеличивает врем , измерени и не позвол ет получить достаточную точность.In the known methods, it is necessary to set the reference level of the microwave signal using an attenuator, which significantly increases the time of measurement and does not allow for obtaining sufficient accuracy.

Известен также способ 2 регистрации сигнала дисперсии электронного парамагнит ного резонанса путем подачи частотно-модулированного напр жени СВЧ, свиппировани подмагничнвающего магнитного пол и выделени в приемнике частоты биений, амплитуда которых пропорциональна производной сигнала дисперсии.Also known is method 2 of detecting the electron paramagnetic resonance dispersion signal by applying a frequency-modulated microwave voltage, sweeping a magnetic field, and extracting a beat frequency in the receiver, the amplitude of which is proportional to the derivative of the dispersion signal.

Однако применение этого способа при измерении ширины линии ФМР сложно, так Kak дл регистрации сигнала дисперсии требуетс частотна модул ци частоты клистрона вспомогательным генератором, выделение сигнала в приемнике, а также измерение характеристик резонатора. Последнее св зано с тем, что на выходе приемной системы получаетс сигнал, обусловленный как влением ФМР образца, так и резонатором. Цель изобретени - упрощение процесса измерени ширины линии ФМР.However, the application of this method in measuring the width of the FMR line is difficult, since Kak requires the frequency modulation of the klystron frequency by an auxiliary generator, signal extraction in the receiver, as well as measurement of the characteristics of the resonator to register the dispersion signal. The latter is due to the fact that at the output of the receiving system a signal is obtained, due to both the phenomenon of FMR of the sample and the resonator. The purpose of the invention is to simplify the process of measuring the width of the FMR line.

Дл этого регистрируют сигнал реакции системы АПЧ на образец и определ ют экстремальные значени частоты генератора приTo do this, the reaction signal of the AFC system to the sample is recorded and the extreme values of the generator frequency at

условии равенства ее резонансной частоты частоте резонатора с помещенным в него образцом, а о ширине линии суд т по измеренным значени м напр женности подмагнйчивающего магнитного пол , соответствующим упом нутым экстремальным значени м .the condition of equality of its resonant frequency to the frequency of the resonator with the sample placed in it, and the line width is judged by the measured values of the intensity of the magnetic field of the magnetizing field corresponding to the mentioned extremal values.

На чертеже схематически изображено устройство, реализующее предлагаемый способ .The drawing schematically shows a device that implements the proposed method.

Устройство содержит клистрон 1, резонатор 2, в который помещен образец, частотомер 3, СВЧ-детектор 4, система АПЧ 5 и магнит 6.The device contains a klystron 1, a resonator 2 in which a sample is placed, a frequency meter 3, a microwave detector 4, an AFC system 5 and a magnet 6.

Claims

The device works as follows. The microwave signal from the output of the klystron is fed to the input of the resonator with the sample and the frequency meter. The signal from the output of the resonator goes to the microwave detector and then “the input of the AFC system and from the output of the All4 system to the reflector of the klystron. The proposed method is implemented as follows. With the help of the AIP system, the initial frequency of klystron generation is set to be equal to the frequency of the resonator with the sample, and then the magnetic field is changed. With the passage of the magnetic field through the resonant region of the sample, the frequency of the resonator with the sample due to the phenomenon of FMR will deviate from the initial one. When this happens, the klystron frequency is set to the frequency of the resonator and corresponds to a certain value of the varying magnetic field. At some values of the magnetic field, the frequency deviations of the klystron reach maximum values, and for one FMR line two extreme values of the frequency will be recorded, and hence two values of the magnetic field. By the difference of the magnetic field values at which the maximum deviations of the klystron generation from the initial, determine the width of the PMI line. The proposed method allows to simplify the process of measuring the width of the ferromagnetic resonance line. The Invention Method for measuring the width of a ferromagnetic resonance line by applying microwave voltage from a signal generator, sweeping a magnetizing magnetic field, changing the frequency of a generator using a frequency control system, and determining the magnetic resonance parameters using a dispersion signal, characterized in that, in order to simplify the measurement of the width of the FMR lines , register the signal of the response of the AFC to the sample and determine the extreme values of the generator frequency under the condition that its resonant frequency is equal to the frequency of the resonator with the sample placed into it, and the line width is judged by the measured values of the intensity of the magnetizing magnetic field corresponding to the mentioned extreme values. Sources of information taken into account in the examination 1. Yakovlev Yu. M., Gendeleva S. Sh. Single crystals of ferrite in radio electronics. M., “Owls. radio, 1975, p. 266-272. 2 USSR Author's Certificate No. 157556, cl. G 01N 27/78, 03.03.62 (prototype).