CONICET | Buscador de Institutos y Recursos Humanos

A variety of doped-semiconducting materials, called diluted magnetic semiconductors (DMS) combine two properties: semiconductivity and magnetism. Many research groups have focused on doping TiO2 with transition metals. Thus, much of the work has concentrated on Co-doped TiO2 films, where, at room temperature, ferromagnetism has been confirmed first for anatase and later also for rutile films. Recently, Co, Fe, Ni, and Mn doped SnO2 have been explored and interesting results were reported, specially in the case of the Co doped system, where a giant magnetic moment was found (7.5 mB/Co atom at romm temperature) [1]. On the other hand, some authors have reported remarkable room temperature ferromagnetism on pure TiO2, HfO2, and In2O3 oxide films [2, 3]a nd also in films doped with non-magnetic impurities [4]. In this work we present a study of the magnetic properties of pure and Fe-doped SnO2 and pure and Fe-doped TiO2 thin films deposited on LaAlO3 by pulsed laser deposition (PLD). The samples were characterized by X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD) and the magnetic properties were measured usin a SQUID. Finally, ab initio calvulations, using full-potential linear augmented plane wave (FP-LAPW) method, were performed. Theoretical and experimental in order to understand the role of the dopant in the origin and significance of the observed ferromagnetism. [1] S. B. Ogale et al., Phys. Rev. 91 (2003) 077205. [2] C. B. Fitzgerald et al., J. Appl. Phys. 95(11) (2004) 7390. [3] N. H. Hong, J. Sakai, W. Prellier and A. Hassini, J. Phys.: Condens. Matter 17 (2005) 1697. [4] Duhalde S, Vignolo M F, Golmar F, Chiliotte C, Rodríguez Torres C E, Errico L A, Cabrera A F, Rentería M, Sánchez F H and Weissmann M Phys. Rev. B 72 (2005) 161313(R).