Phase Separation in the Double Perovskite Sr2FeNbO6-δ

Abstract

The ceramic perovskite Sr2FeNbO6-δ was synthesized via the solution combustion precursor method. X-ray phase analysis showed that the sample is single-phase and does not contain impurities. The specific heat capacity and the Mössbauer spectra were measured for the Sr2FeNbO6-δ ceramic in the temperature range of 4–300 K. The observation of an asymmetric doublet in the Mössbauer spectra and the literature data on the magnetic susceptibility indicated the presence of two magnetic subsystems in Sr2FeNbO6-δ with antiferromagnetic exchange interactions. Based on the analysis of the temperature dependence of the specific heat capacity, we determined the Debye and Einstein temperatures.