Cab initio study of Fe-doped SnO2

A. M. MUDARRA NAVARRO; L. A. ERRICO; V. BILOVOL; A. F. CABRERA; C. E. RODRÍGUEZ TORRES

Lima, Peru

Conferencia; XII Latin American Conference on Mossbauer Effect; 2010

Universidad de Lima, Peru

Trabajo presentado e forma de poster durante la reunion In this work we present an ab initio study of Fe-doped SnO2. The calculation were performed using the APW+lo method.  We report hyperfine parameters at the Fe site and the equilibrium interatomic distances for different impurity-oxygen vacancies configurations and for two Fe concentrations. The predictions are compared with experimental results obtained by Mossbauer and X-ray absorption spectroscopies of powder samples prepared by mechanosynthesis and sol-gel. The comparison between experimental and theoretical results for the hyperfine parameters (isomer shift and quadrupole splitings) and Fe-O bond-lengths allow us to conclude that the oxygen vacancies are located in the first coordination sphere of Fe atoms in all the samples studied. Additionally, we study the magnetic alignment between Fe atoms considering different distributions of impurities in the SnO2 host. Our results show that the coupling is antiferromagnetic when the Fe atoms share oxygen atoms, but the system becomes ferromagnetic when vacancies are located between irons.