Evidence for an anomalous redox ionic pair between Ru and Mn in SrRu0.5Mn0.5O3: An X-ray absorption spectroscopy approach

Abstract

X-ray absorption spectroscopy studies of the polycrystalline SrRu_0.5Mn_0.5O₃ have been performed at Ru, Mn-L_2,3 edges. The 2p → t_2g related peak at the Ru-L₂ edge is more intense than the Ru-L₃ edge and a shift of the 2p → e_g related peak by ∼0.8 eV to higher energy than that of the Ru(IV) compound, SrRuO₃ is observed. In combination with a crystal field multiplet calculation approach, a possible anomalous change in the spectral features is explained based on the existence of a redox ionic pair involving Ru(IV)/Ru(V) ↔ Mn(III)/Mn(IV).