Magnetic proximity effect in La₀.7Ca₀.₃MnO₃/La₀.₉Ca₀.₁MnO₃ multilayered film with diffusive interfaces

Abstract

The structural, the magnetic and the transport properties of La₀.7Ca₀.₃MnO₃/La₀.₉Ca₀.₁MnO₃ multilayer film, prepared by rf-magnetron sputtering, have been investigated. The high-resolution electron-microscopy studies reveal the formation of different crystal structures in the constituent sublayers, but without sharp and well-defined interfaces. At the same time, the small regions of double-period modulated phase exist in the La₀.₉Ca₀.₁MnO₃ sublayers at room temperature, manifesting the formation of charge-ordered antiferromagnetic state. The magnetic measurements reveal a significant enhancement of the ferromagnetic ordering in the La₀.₉Ca₀.₁MnO₃ layers due to a strong magnetic coupling between the constituent sublayers. The multilayer film shows the anisotropic saturation magnetization at low temperature and the alternating shape of the temperature-dependent anisotropic magnetoresistance near the metal–insulator transition.