Гигантский магниторезистивный эффект в отражении микроволн от сверхрешеток (CoFe)/Cu

Experimental study of microwave giant magnetoresistive effect in wave reflection has been carried out in frequency range from 26 to 38 GHz. The magnitude of the effect is obtained and its magnetic field dependence is defined. The experiments are carried out with (CoFe)/Cu superlattices, which have giant magnetoresistance. Calculations of the magnetic field dependence of microwave reflection coefficient are fulfilled. The measured values of reflection coefficient variations are found to be greater than the calculated ones. This difference is connected with approximation within which the superlattice is replaced by the uniform metallic plate in calculations. A frequency dependence of microwave giant magnetoresistive effect in reflection is also observed. This dependence is explained by the influence of the waveguide impedance where the sample is placed in measurements.

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Ферромагнитных резонанс в прохождении электромагнитных волн через металлические сверхрешетки

Журнал технической физики ◽

10.21883/jtf.2021.06.50871.230-20 ◽

2021 ◽

Vol 91 (6) ◽

pp. 995

Author(s):

А.Б. Ринкевич ◽

Е.А. Кузнецов ◽

Д.В. Перов ◽

М.А. Миляев ◽

Л.Н. Ромашев

Keyword(s):

Magnetic Field ◽

Transmission Coefficient ◽

Field Dependence ◽

Ferromagnetic Resonance ◽

Resonance Line ◽

Magnetic Field Dependence ◽

Microwave Transmission ◽

Giant Magnetoresistive Effect ◽

Magnetoresistive Effect ◽

Dispersion Line

Variations of microwave transmission coefficient through Fe films and Fe/Cr superlattices have been studied caused by ferromagnetic resonance at frequencies from 26 to 38 GHz. The shape of resonance line is described in frames of the model where its asymmetry is obtained by adding of lorenzian dispersion line to the absorption line. It has been shown that the shape of resonance line for superlattices with continuous Fe and Cr layers and also for Fe films is well described in this model. For the superlattices with thin Fe or Cr layers only qualitative agreement is observed. In magnetic fields less than the field of ferromagnetic resonance, essential distinction is observed of experimental magnetic field dependence of transmission coefficient comparing to the model, for superlattices which have giant magnetoresistive effect.

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Nanocomposite with Non-Spherical Granules – Logarithmic Field Dependence of Giant Magnetoresistance

MRS Proceedings ◽

10.1557/proc-674-u5.7 ◽

2001 ◽

Vol 674 ◽

Author(s):

E. Meilikhov ◽

B. Raquet

Keyword(s):

Magnetic Field ◽

Simple Model ◽

Field Dependence ◽

Giant Magnetoresistance ◽

Magnetic Field Dependence ◽

Logarithmic Function ◽

The Magnetic Field

ABSTRACTMagnetoresistance of the nanocomposite Fex(SiO2)1−x (x≍0.6) at high enough magnetic field is logarithmic function of the magnetic field. Such a dependence does not fall into the known theory of giant magnetoresistance of ferromagnetic nanocomposites. This paper examines the giant magnetoresistance of such a system in terms of a simple model where the non-ordinary quasi-logarithmic magnetic field dependence of nanocomposite magnetoresistance is related to the non-spherical granules' distribution over their shapes.

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