We present a comprehensive study of CaCu3Ru4O12 using bulk sensitive hard and soft x-ray spectroscopy combined with local-density approximation+dynamical mean-field theory (DMFT) calculations. Correlation effects on both the Cu and Ru ions can be observed. From the Cu 2p core-level spectra, we deduce the presence of magnetic Cu2+ ions hybridized with a reservoir of itinerant electrons. The strong photon energy dependence of the valence band allows us to disentangle the Ru, Cu, and O contributions and, thus, to optimize the DMFT calculations. The calculated spin and charge susceptibilities show that the transition metal oxide CaCu3Ru4O12 must be classified as a Kondo system and that the Kondo temperature is in the range of 500-1000 K.
ASJC Scopus subject areas
- Physics and Astronomy(all)