Magnetorefractive effect in the La1−xKxMnO3 thin films grown by MOCVD

•Giant magnetorefractive effect was obtained in La1−xKxMnO3 films in the infrared.•Inhomogeneity as well as doping level strongly influences the value of magnetorefractive effect.•Resonance-like bands have been observed in the magnetoreflection spectra of the films.•The obtained experimental data can be explained in the framework of the MRE theory.

Thin epitaxial La1−хKхMnO3 films were grown using two-stage procedure. Influence of substitution of La3+ ions with K+ ions on the optical and electrical properties of La1−xKxMnO3 films (х=0.05, 0.10, 0.15 и 0.18) has been studied in detail. A noticeable magnetorefractive effect in the films under study was detected in the infrared range. Magnetorefractive effect as well as transverse magneto-optical Kerr effect and magnetoresistance have the maximum in optimally doped sample with x=0.18 corresponding to the highest Curie temperature. The experimental data for compositions close to optimally doped films are in good agreement with the data calculated in the framework of a theory developed for manganites. The resonance-like contribution to magnetoreflection spectra of manganite films has been observed in the vicinity of the phonon bands. It is shown that magnetic and charge inhomogeneities strongly influence on the magneto-optical effects in films. Thin films of La1−xKxMnO3 with the large values of Kerr and magnetorefractive effect are promising magneto-optical material in the infrared range.