We report bulk-sensitive hard x-ray $(h\nu =5.95\mathrm{keV})$ core-level photoemission spectroscopy (PES) of single crystal ${\mathrm{V}}_{1.98}{\mathrm{Cr}}_{0.02}{\mathrm{O}}_3$ and the high-$T_c$ cuprate ${\mathrm{Bi}}_2{\mathrm{Sr}}_2\mathrm{Ca}{\mathrm{Cu}}_2{\mathrm{O}}_{8+\delta }$ (Bi2212). ${\mathrm{V}}_{1.98}{\mathrm{Cr}}_{0.02}{\mathrm{O}}_3$ exhibits low binding energy “satellites” to the V $2p$ “main lines” in the metallic phase, which are suppressed in the antiferromagnetic insulator phase. In contrast, the Cu $2p$ spectra of Bi2212 do not show temperature-dependent features, but a comparison with soft x-ray PES indicates a large increase in the $2p^{5}3d^9$ satellites or $3d^9$ weight in the bulk. Cluster model calculations, including a full multiplet structure and a screening channel derived from the coherent band at the Fermi energy, give very satisfactory agreement with the experiments.

• Received 21 January 2005

DOI:https://doi.org/10.1103/PhysRevB.71.155102