Abstract
We report x-ray photoelectron spectroscopic investigation of with ferromagnetic and a superconducting transition temperature of compared with , which is a ferromagnetic insulator. Our results show that the rare earths, Eu and Ce, are in and states, respectively. Comparing the Ru core level spectra from these compounds to those from two Ru reference oxides, we also show that Ru in these ruthenocuprates is always in state, suggesting that the doped holes in the superconducting compound arising from the substitution of by are primarily in the Cu-O plane, in close analogy to all other doped high- cuprates. Analysis of Cu spectra in terms of a configuration interaction model provides a quantitative description of the gross electronic structures of these ruthenocuprates.
- Received 31 July 2006
DOI:https://doi.org/10.1103/PhysRevB.74.245106
©2006 American Physical Society