Bulk-sensitive photoemission spectroscopy of A(2)FeMoO(6) double perovskites (A = Sr, Ba)

Abstract

The electronic structures of Sr2FeMoO6 (SFMO) and Ba2FeMoO6 (BFMO) double perovskites have been investigated using Fe 2p-->3d resonant photoemission spectroscopy (PES) and the Cooper minimum in the Mo 4d photoionization cross section. The states close to the Fermi level are found to have a strongly mixed Mo-Fe t(2g) character, indicating that the Fe valence is far from pure 3+. The Fe 2p(3/2) x-ray absorption spectroscopy spectra reveal the mixed-valent Fe3+-Fe2+ configurations, and a larger Fe2+ component for BFMO than for SFMO, suggesting an operative double exchange interaction. The valence-band PES spectra reveal good agreement with the local-spin-density-approximation (LSDA)+U calculation.