INVESTIGADORES
MUDARRA NAVARRO Azucena Marisol
congresos y reuniones científicas
Título:
Relation between structural and magnetic properties in (Ti,Fe)O2 powders obtained by mechanical milling
Autor/es:
A.M. MUDARRA NAVARRO, V. BILOVOL, A.F. CABRERA AND C.E. RODRÍGUEZ TORRES.
Lugar:
Buenos Aires
Reunión:
Workshop; At the Frontiers of Condensed Matter IV; 2010
Institución organizadora:
Comisiín Nacional de Energía Atómica
Resumen:
Fe-doped TiO2 samples with different Fe content were prepared by mechanical alloying starting from TiO2 rutile and FeO. The samples were structurally and magnetically characterized by XRD, Mössbauer spectroscopy, X ray absorption spectroscopy (XAS), AC-susceptibility and magnetization measurements. XAS results showed that Fe ions are incorporated into the rutile phase with oxygen coordination lower than that expected in this phase. The oxygen coordination number decreases with the increase of Fe2+ ions such as it was previously found in milled samples of TiO2 doped with hematite. The RT Mössbauer spectra were reproduced using two paramagnetic interactions, one corresponding to Fe2+ (δ~0.87 mms-1) and the other to Fe3+ (δ ~0.31 mms-1). Magnetometry measurements showed the presence of paramagnetic and ferromagnetic-like interactions at room temperature. Although saturation and coercivity of the ferromagnetic phase increases with iron, the effective magnetic moment per iron atom decreases, probably due to the precipitation of Fe rich antiferromagnetic structures.