Магнитоотражение и эффект Керра в пленках La-=SUB=-2/3-=/SUB=-Ba-=SUB=-1/3-=/SUB=-MnO-=SUB=-3-=/SUB=- с вариантной структурой

A correlation was found between the magnetoreflection of natural light and tunneling magnetoresistance in La2 / 3Ba1 / 3MnO3 films with a variant structure grown on ZrO2 (Y2O3) substrates. It was shown that the magnetoreflection as well as the colossal magnetoresistance, is maximum in the region of magnetic ordering near room temperature (Tc ~ 295 K) of the films. The magnetoreflection spectra of a La2 / 3Ba1 / 3MnO3 film with the variant structure are formed by the same mechanisms as in the case of films without the variant structure and can be described in terms of the theory of the magnetorefractive effect. The field and temperature dependences of magnetoreflection demonstrate the presence of an additional low-temperature contribution to the reflection of the La2 / 3Ba1 / 3MnO3 film due to tunneling of spin-polarized electrons through the boundaries of structural domains.

Features of Modeling of the Magnetorefractive Effect in Multilayered Metal Nanostructures

The magnetorefractive effect (MRE) is important and interesting from both fundamental and practical points of view. This effect consists in a change in the reflection coefficient or the passage of an electromagnetic wave from magnetized structures with magnetoresistance effects. It can be giant, tunnel and colossal magnetoresistance depending on the type of structure. MRE is most clearly manifested in the IR region of the spectrum and can reach tens of percent. It is possible to show its unambiguous dependence on the magnitude of the magnetoresistance. This article discusses the features of MRE in multilayer metal nanostructures with giant magnetoresistance. The MRE simulation is carried out using a model that relates this effect to magnetoresistance, as well as in the framework of the model taking into account spin-dependent scattering. The last model in earlier works allowed describing a number of experimental data well qualitatively and in some places quantitatively. In this paper, taking into account the frequency dependence of the resistance allowed us to improve the first model, which allowed us to obtain a good qualitative and quantitative description of the effect value – this is a fundamentally new result. The article highlighted the key opportunity for the application of magnetorefractive effect as a contactless method to study nanostructures, a method of nondestructive testing of all electronic components. A comparison with experimental data is also made. A good description is demonstrated in the framework of the two models considered, which can effectively describe the relationship between MRE and magnetoresistance.

Особенности магниторефрактивного эффекта в многослойной металлической наноструктуре [CoFe/Cu]-=SUB=-n-=/SUB=--=SUP=-*-=/SUP=-

The features of magnetorefractive effect (MRE) in metallic multilayer film Ni_48Fe_12Cr_40(50 Å)/[Co_90Fe_10(14 Å)/Cu(22 Å)]_8/Cr(20 Å) nanostructures, which exhibit giant magnetoresistance at room temperature, are investigated experimentally and theoretically. We show that the MRE in these structures reaches 1.5% in an applied magnetic field of 3.5 kOe, in a broad part of the IR region, and can change sign for both transmission and reflection of light. The refraction and extinction coefficients that are calculated for the nanostructures in an external magnetic field are in good agreement with our experimental data. The deduced formulas can be applied to estimating the MRE in multilayer metallic nanostructures.