Spectroscopic investigation of AS defects on the electronic structure of Sr2FeMoO6

D RUBI; J. NAVARRO; J. FONTCUBERTA; M. IZQUIERDO; J. AVILA; M.C. ASENSIO

Sitges, Espana

Congreso; Spectroscopies in Novel Superconductors; 2004

We report here on the effect of antisite defects on the band structure of Sr2FeMoO6 (SFMO), as determined from photoemission (PES) and X-ray absorption (XAS) spectroscopy. In the first place, we have analyzed the core levels of both Fe and Mo ions, finding that their structure remainsunmodified upon varying the antisite concentration. Additionally, we have found Mo being in a mixed state (Mo+6/Mo+5 in a 66/34% ratio), while Fe valence was in the range +2.6–+2.8. Second, we studied the valence band of SFMO, finding that the Mo-projected density of states atthe Fermi level (D(EF)) is increased when the antisite concentration lowers. A correlation between D(EF) and the Curie temperature is proposed.