Electron Transitions between Grain Boundaries in the (La1.85Sr0.15CuO4)1-x(La0.5Sr0.5MnO3)x Composites

Abstract

The composites of polycrystalline (La1.85Sr0.15CuO4)1-x(La0.5Sr0.5MnO3)x were prepared by solid state reaction method. By means of X-ray absorption spectroscopy, it is found that electrons can transit at grain boundaries from La1.85Sr0.15CuO4 to La0.5Sr0.5MnO3. Additional holes are formed in La1.85Sr0.15CuO4 when the electron transitions happen. The experimental results of both X-ray absorption near edge structure and extended X-ray absorption fine structure excluded the possibility of that the electron transitions are induced by local lattice structure. According to the X-ray absorption experimental results of O K-edge of the La1.85Sr0.15CuO4 and La0.5Sr0.5MnO3 materials, a possible mechanism of the electron transitions and a phenomenological model of the band structure around Fermi level are proposed to explain the transition behavior.