Hydrothermal synthesis and 121Sb Mössbauer characterization of perovskite-type oxides: Ba2SbLnO6 (Ln = Pr, Nd, Sm, Eu)

A mild hydrothermal process to prepare Ba2SbLnO6 (Ln = Pr, Nd, Sm, Eu) perovskite-type oxides are presented. These perovskites were characterized on the basis of X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), inductively-coupled plasma spectra (ICP) techniques. Primary structure was confirmed using Rietveld method based on XRD data shows that the likely space groups of Ba2SbLnO6 are R-3 for Ln = Pr and Nd and Fm-3m for Ln = Sm and Eu, respectively. The measurement of Mössbauer effect of the 37.2 keV γ transition of 121Sb indicates that the isomer shift of these perovskites falls in the region of the Sb5+ and reflects some hybridized-orbital behavior in Sb-O bonds.