Study of Kb X-ray emission spectroscopy applied to Mn(2x)V(1-x)O4 (x=0 and1/3) oxyspinel and comparison with XANES

Abstract

Oxidation state and coordination of transition metal cations seems to be hard to assess when considering multiple cations, each one with different possible oxidation states. In fact, this is the case of the spinel-type double oxides family. High resolution Kβ X-ray fluorescence spectra were measured in Mn(2−x)V(1+x)O4 (x=0 and 13) spinels-type double oxides in order to determine the oxidation state and coordination of V and Mn cations. The relative intensity of radiative Auger effect KM2,3M4,5 to the total intensity and the integral absolute difference value were used as reference parameters for the characterization of Mn oxidation states. The coordination of Mn ions was inferred by the intensity of the Kβ5 line. In the case of V compounds, it was used as the intensity of the line Kβ′ relative to the total area of Kβ region. The obtained results were further compared with X-ray absorption spectra analysis, showing good agreements regarding the oxidation state characterization. However, there were found some discrepancies in coordination, due to customary oversimplifications in the Kβ5 line origin. The obtained results might represent valuable and useful data for chemical scopes of characterizing spinel-type oxides family.