XAFS and CEMS study of dilute magneto-optical semiconductor, Fe doped TiO2 films

TiO2 films doped with 6% Fe were prepared by pulsed laser deposition (PLD) under different oxygen pressures, and characterized by X-ray absorption fine spectra (XAFS) and conversion electron Mössbauer spectra (CEMS). The edge energy and spectrum profiles of Fe– and Ti K X-ray absorption showed only Fe3+ and Ti4+ states for rutile TiO2 films prepared under 10− 1 Torr, the metallic Fe and Ti4+ for rutile TiO2 films prepared in 10− 6 Torr, and the metallic Fe and the average valance of less than “4+” for Ti in TinO2n−x films prepared by the PLD under 10− 8 Torr. The metallic Fe clusters are also found in the TEM images of TinO2n−x film. Magnetic property of Fe doped TiO2 films prepared by PLD at high vacuum (10− 6 and 10− 8 Torr) is considered to originate mainly from the magnetic metal iron clusters.