On the Valence State of Iron in Sr0.52+Ca0.52+Fe0.54+ Me0.54+O32−

Abstract

Powder samples of Sr0.5Ca0.5Fe0.5Me0.5O3 (Me = Co, Zr or Mn) and Sr0.3La0.7FeO3 are investigated by X-ray diffraction and Mossbauer effect spectroscopy.

Analysis of the completely ordered spectra suggested three kinds of iron ions coexist in general where the resolution into the different valence state is clearly seen. The Mossbauer effect parameters values are found to be close to those expected for Fe3+, Fe4+ and Fe5+ indicating that some of the tetravalent iron ions in its high spin state disproportionate into Fe3+ and Fe5+ ions passing through temperature dependent intermediate valence states.