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 [1] and rutile [2] TiO2 has stimulatedintense theoretical and experimental studies of these systemsdue to their potential applications in spintronic technology.In effect, dilute magnetic semiconductors (DMS), producedby doping non magnetic semiconductors with transition metals,combine their electric conductivity with ferromagnetismand 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 [3], equivalentto what would be expected if, on the average, each Cuatom bears a magnetic moment of about 1.5 μB.In order to clarify the role of impurities in the magnetism ofDMS it is crucial to determine the local environment of magneticand non magnetic impurities. In this work we presentan EXAFS (Extended X-ray Absorption Fine Structure) andXANES (X-ray Absorption Near Edge Spectroscopy) characterizationof the local environment of transition metal (TM)-doped anatase TiO2 thin films (TM=Co, Ni and Zn).