Electronic study of Al substituted La0.7Ca0.3MnO3 using photoemission spectroscopy

Polycrystalline samples of La0.7Ca0.3Mn1−XAlXO3 (X=0, 0.05, 0.15) are prepared using solid state reaction route. Photoemission spectroscopy measurements were performed on these samples to investigate their electronic properties. Al shows 3+ oxidation state in both Al doped samples while no effect of Al doping is found on the core level spectrum of La 4d and Ca 2p orbitals and they were found in 3+ and 2+ oxidation state respectively in all the samples . Mn 2p core level photoemission measurements indicates that for 5% Al doped sample (lower doping) Al ions replaces the Mn3+ ions while they substitute Mn4+ in 15 % Al doped sample ((higher doping).