Evolution of Mn and Co oxidation state on TbMn1-xCoxO3 compounds

Abstract

Structural and electronic properties of TbMn1-xCoxO3 samples have been characterized by means of x-ray and neutron diffraction and x-ray absorption spectroscopic techniques. Crystallographic structure was refined from diffraction data, and samples show the orthorhombic distorted perovskite structure (Pbnm), being isostructural to TbMnO3, except for x=0.4, 0.5 and 0.6, where an ordered double perovskite structure (P21/n) is found. The electronic configuration of Mn and Co ions was obtained along the series from the chemical shift of the edge on x-ray absorption spectra, at the Mn and Co K-edges. Our results agree with a charge redistribution between Mn and Co ions, yielding a mixed valence state Mn3+/Mn4+ and Co3+/Co2+ for the whole series.