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 La 2/3 Ba 1/3 MnO 3 films with a variant structure grown on ZrO 2 (Y 2 O 3 ) 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 ( T C ≈ 295 K). Magnetoreflection spectra of a La 2/3 Ba 1/3 MnO 3 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 La 2/3 Ba 1/3 MnO 3 film due to the tunneling of spin-polarized electrons through structural domain boundaries.