Photoemission spectroscopy and x-ray absorption spectroscopy studies of double perovskite oxides: Ba2-xLaxFeMoO6

Abstract

Electronic structures of La-doped Ba2FeMoO6 double perovskite oxides have been investigated using photoemission spectroscopy and soft x-ray absorption spectroscopy. The ground states of Ba2-xLaxFeMoO6 are found to be in the Fe2+-Fe3+ mixed-valent states and the Fe valence state increases toward 3+ with increasing x. The states close to E-F consist of the degenerate Mo-Fe t(2g)down arrow states. The LSDA + U calculations for Ba2-xLaxFeMoO6 (x = 0, 1) show a larger occupied bandwidth of the Mo t(2g)down arrow states for x = 1 than for x = 0, which is consistent with the higher T-C value predicted in a type of the double exchange mechanism.