The relationship between magnetic behaviour and local structure around Fe ions in Fe-doped TiO2 rutile.

A. M. MUDARRA NAVARRO, V. BILOVOL, A. F. CABRERA, C.E. RODRÍGUEZ TORRES AND F. H. SÁNCHEZ

PHYSICA B - CONDENSED MATTER

SLSEVIER SCIENCE

Año: 2009 vol. 404 p. 2838 - 2840

0921-4526

The magnetic and structural characterization of Ti1-xFexO2 (x= 0.025, 0.05, 0.07, 0.125 and 0.15) samples, prepared by mechano-synthesis using TiO2 and Fe2O3 as starting materials are reported. XANES measurements performed at the Fe K-edge show that Fe ions are in 3+ oxidation state in the 7 at. % Fe doped sample and in a mixture of 2+ and 3+ oxidation states in the others samples. EXAFS results show the incorporation of Fe ions substituting Ti ones in the rutile TiO2 structure. They also reveal a strong correlation between the number of oxygen nearest neighbours and the Fe2+ fraction, i.e the number of oxygen near neighbours decrease when the Fe2+ fraction increases. All samples present ferromagnetic-like behaviour at room temperature.  We found a clear dependence between saturation magnetization and coercivity with the fraction of Fe2+ and/or the number of Fe near neighbour oxygen vacancies.