Local atomic and electronic structure in nanocrystalline Sn-doped anatase TiO2

Tin-doped anatase TiO2 nanopowders and nanoceramics with particle sizes between 12 and 30 nm are investigated by X-ray absorption fine-structure (EXAFS) and Mossbauer spectroscopies. Furthermore, ab initio calculations based on the density functional theory are performed to analyze changes in the electronic structure due to Sn doping. The three approaches consistently show that Sn is dissolved on substitutional bulk sites with a slight increase of the bond lengths of the inner coordination shells. The Debye-Waller factors show that the nanocrystallites are highly ordered. There is no indication of defect states or bandgap changes with Sn doping.