Electronic structure of magnetic semiconductor CdCr2Se4: Cr 3d partial density of states and p-d hybridization

Abstract

We have studied the contribution of Cr 3d states to the valence bands of CdCr2Se4 by means of the resonant enhancement of the Cr 3d photoemission cross section near the Cr 3p → 3d core excitation ( h {combining short stroke overlay}ω = 47 eV). The Cr 3d partial density of states (DOS) is evaluated from the spectra taken on and off resonance. A strong peak in the partial DOS located at 1.3 eV below the valence band maximum is assigned to the t2g ↑ bands without strong dispersion. The second peak located at 2.9 eV is mainly derived from the eg ↑ and eg ↓ bands, which are spread over in the valence band region between 0 and 5 eV due to the strong p-d hybridization. The results are qualitatively interpreted in terms of a molecular-orbital level-scheme and compared with the results of band-structure calculation based on the DV-Xα method. © 1989.