XAS study of the local environment of impurities in doped TiO2 thin films

A.M. MUDARRA NAVARRO, RODRÍGUEZ TORRES, C. E., F. GOLMAR, L. A. ERRICO, A.F. CABRERA, M. RENTERÍA, AND F.H. SÁNCHEZ

LNLS Activity Report 2006

Brazilian Synchrotron Light Laboratory

Lugar: Campinas (Brasil); Año: 2007 p. 1 - 2

The discovery of room-temperature ferromagnetism (RTF) in Co-doped anatase and rutile  TiO2 has stimulated intense theoretical and experimental studies of these systems due to their potential applications in spintronic technology. In effect, dilute magnetic semiconductors (DMS), produced by doping non magnetic semiconductors with transition metals, combine their electric conductivity with ferromagnetism and optical transparency, thereby opening up the possibility ofnew device concepts. Recently, we reported the experimental observation of unexpectedand significant RTF in Cu-doped TiO2 films, equivalent to what would be expected if, on the average, each Cu atom bears a magnetic moment of about 1.5 μB. In order to clarify the role of impurities in the magnetism of DMS it is crucial to determine the local environment of magneticand non magnetic impurities. In this work we present an EXAFS (Extended X-ray Absorption Fine Structure) and XANES (X-ray Absorption Near Edge Spectroscopy) characterizationof the local environment of transition metal (TM)-doped anatase TiO2 thin films (TM=Co, Ni and Zn).