Synchrotron-radiation study of Fe 3dstates inCd1−xFexSe (0≤x≤0.4)

The electronic structure of ${\mathrm{Cd}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Fe}}_{\mathrm{x}}$Se (0≤x≤0.4) has been investigated by synchrotron-radiation photoemission in the photon energy range from 47 to 62 eV. Valence-band photoemission spectra of ${\mathrm{Cd}}_{0.6}$ ${\mathrm{Fe}}_{0.4}$Se exhibit Fe-derived narrow peaks at 0.5 and 3.7 eV below the valence-band maximum. These structures are assigned to emission from the Fe 3d↓ and 3d↑ states with $e_g$ symmetry, respectively. The $t_{2g}$ components hybridize appreciably with the Se 4p states and contribute throughout the top 6 eV of the valence bands. The results are qualitatively interpreted in terms of a molecular-orbital level scheme.