INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
congresos y reuniones científicas
Structural and magnetic characterization of Ti1-xFexO2 (2.5
MUDARRA NAVARRO A.M., BILOVOL V., CABRERA A.F., RODRIGUEZ TORRES., C.E., AND SANCHEZ, F.H.
Workshop; At the Frontiers of Condensed Matter IV: Current Trends and Novel Materials (FCM2008); 2008
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 Fe K-edge show that Fe ions are in 3+ oxidation state in 7 at. % Fe doped sample and in a mixture of 2+ and 3+ oxidation states in the others samples. EXAFS results show a good incorporation of Fe ions substituting Ti ones in the rutile TiO2 structure. Besides, EXAFS reveals a strong correlation between the number of oxygen nearest neighbours and Fe2+ fraction, i.e the number of oxygen near neighbour decreases when Fe2+ fraction increases. All samples present ferromagnetic-like behaviour at room temperature. We found a clear dependence between saturation magnetization and coercivities with the fraction of Fe2+ and/or the number of oxygen vacancies near neighbours of the Fe ions.