Magnetoreflection and Kerr Effect in La2/3Ba1/3MnO3 Films with a Variant Structure

A correlation between the effect of magnetoreflection of natural light and tunnel magnetoresistance has been found in La2/3Ba1/3MnO3 films with a variant structure grown on ZrO2(Y2O3) substrates. It is shown that the magnetoreflection effect and giant magnetoresistance in these films are maximum in the region of magnetic ordering near room temperature (TC ≈ 295 K). Magnetoreflection spectra of a La2/3Ba1/3MnO3 film with a variant structure are formed via the same mechanisms as for films without a variant structure and can be described within the theory of the magnetorefractive effect. The field and temperature dependences of the magnetoreflection exhibit the presence of an additional low-temperature contribution to the reflection of a La2/3Ba1/3MnO3 film due to the tunneling of spin-polarized electrons through structural domain boundaries.