Fe-doped rutile SnO2: local structure vs. hyperfine parameters

A.M. MUDARRA NAVARRO , C. E. RODRÍGUEZ TORRES, A. F. CABRERA AND L. A. ERRICO; M. WEISSMANN

Medellín

Conferencia; XIII Latin American Conference on the Applications of the Mössbauer Effect - LACAME 2012; 2012

During the last years the study of transition-metal-doped TiO2 and SnO2 semiconductors has become a topic of interest, not only because of the many current industrial applications of these materials but also because of their potential use in spintronic devices. Among other techniques, Mössbauer Spectroscopy was largely applied to study these systems. However, contradictory results were obtained, and several questions remain open concerning the location of the Fe dopants in the host structure, and/or the short range orders around impurities, as well as the assignment of the observed hyperfine interactions. We present here an ab initio study (using the full-potential augmented plane wave plus local orbital, APW+lo method) of Fe-doped rutile SnO2. We performed calculations of hyperfine parameters at Fe impurities as a function of the Fe-dopant and oxygen vacancy concentrations and distribution in the hosts and assuming substitutional and interstitial sites for Fe in the structure. The magnetic allignment and the role of the different variables on it, it is discussed and compared with available experimental data.