Phase and valence transitions in Ba2LnSnxNb1−xO6−δ

The series Ba2LnSnxNb1−xO6−δ (Ln=Pr and Tb) has been investigated using powder diffraction and spectroscopic techniques. Similarly to the analogous Sb5+ containing compounds it was found that Sn4+ doping leads to the gradual oxidation of the Ln3+ cations to the Ln4+ state. Quantitative analysis of the Ln LIII-edge absorption spectra indicates that few or no oxygen vacancies are present.