57Fe and 151Eu Mössbauer study of charge disproportionation and magnetic properties in Eu1/3Sr2/3FeO3

In this work, the study on charge disproportionation and magnetic property in perovskite sample, Eu1/3Sr2/3FeO3, is presented. The sample was prepared by conventional method of solid-state reaction and was found as a single phase with orthorhombic structure. 57Fe and 151Eu Mössbauer spectra have been measured at the temperatures ranging from 360 K to 15 K. The intensity ratio of the 57Fe Mössbauer spectra corresponding to the Fe3+ and Fe4+ at paramagnetic state is found with the ratio 60:40, and a typical ratio corresponding to Fe3+ and Fe5+ is observed as about 70:30 below 90 K, which indicates charge disproportionation (CD) as 2Fe4+ → Fe3+ + Fe5+ and a typical magnetic relaxation phenomenon have taken place between 270 K and 90 K. Also, the much broadened absorption peaks with decreasing temperature at 151Eu Mössbauer spectra provide another evidence of magnetic relaxation properties in this compound.