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

Abstract In this work, the study on charge disproportionation and magnetic property in perovskite sample, Eu 1/3 Sr 2/3 FeO 3 , is presented. The sample was prepared by conventional method of solid-state reaction and was found as a single phase with orthorhombic structure. 57 Fe and 151 Eu Mossbauer spectra have been measured at the temperatures ranging from 360 K to 15 K. The intensity ratio of the 57 Fe Mossbauer spectra corresponding to the Fe 3+ and Fe 4+ at paramagnetic state is found with the ratio 60:40, and a typical ratio corresponding to Fe 3+ and Fe 5+ is observed as about 70:30 below 90 K, which indicates charge disproportionation (CD) as 2Fe 4+  → Fe 3+  + Fe 5+ 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 151 Eu Mossbauer spectra provide another evidence of magnetic relaxation properties in this compound.