Hydrothermal synthesis and ~(121)Sb Mossbauer characterization of perovskite-type oxides: Ba_2SbLnO_6 (Ln=Pr, Nd, Sm, Eu)

摘要

A mild hydrothermal process to prepare Ba_2SbLnO_6 (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 Ba_2SbLnO_5 are R-3 for Ln=Pr and Nd and F_m-3_m for Ln = Sm and Eu, respectively. The measurement of Mossbauer effect of the 37.2 keV γ transition of ~(121)Sb indicates that the isomer shift of these perovskites falls in the region of the Sb~(5+) and reflects some hybridized-orbital behavior in Sb-0 bonds.