Valence measurement of Mn oxides using Mn K-beta emission spectroscopy

High resolution Mn K-beta emission spectra provide a direct method to probe the effective spin state and charge density on Mn sites. Direct comparison of MnF2 and MnO reveals significant changes due to the degree of covalency . The detailed shape and energy shift of thr spectra for the perovskite LaM nO3 and CaMnO3 compounds are found to be very similar to Mn2O3 and MnO2, re spectively. Detailed Mn K-beta X-ray emission results on La1-xCaxMnO3 can b e well fit by linear superpositions of the end member spectra. However, for x < 0.3, a retarded response is found. No evidence for Mn2+ is found. (C) 2000 Elsevier Science Ltd. All rights reserved.