Magnetic proximity effect in La0.7Ca0.3MnO 3/La0.9Ca0.1MnO3 multilayer films with diffusive interfaces

Abstract

The structural, magnetic, and transport properties of La0.7 Ca0.3 MnO3/La0.9 Ca0.1 MnO 3 multilayer films prepared by rf-magnetron sputtering are investigated. 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, small regions of double-period modulated phase exist in the La0.9 Ca0.1 MnO3 sublayers at room temperature, manifesting the formation of a charge-ordered antiferromagnetic state. The magnetic measurements reveal a significant enhancement of the ferromagnetic ordering in the La0.9 Ca 0.1 MnO3 layers due to a strong magnetic coupling between the constituent sublayers. The multilayer films show anisotropic saturation magnetization at low temperature and an alternating shape of the temperature-dependent anisotropic magnetoresistance near the metal-insulator transition. © 2008 American Institute of Physics.