Transition metal 3d states in HgSe-based diluted magnetic semiconductors

The contributions of Mn3d, Fe3d and Co3d electrons to the valence band elec tronic structure of Hg1-xTMxSe (TM=Mn, Fe, Co) crystals were investigated b y means of resonant photoemission. The comparison of photoemission spectra with the results of theoretical calculations made by the CPA (coherent pote ntial approximation) method shows that the valence band of Hg1-xTMxSe dilut ed magnetic semiconductors is strongly influenced by TM3d electrons. We fin d out that for all TM incorporated in the HgSe matrix. 3d electrons with t( 2g) symmetry hybridize strongly with the valence band of the crystal, where as 3d electrons with e(2g) symmetry are not hybridized with the valence ban d. The contribution of 3d(e2g) electrons is spread over the valence band wi th the maximum at 3.4-3.8 eV below the Fermi level. The contributions of 3d (e2g) electrons were found in the middle part of the valence band and, in t he Fe and Co case, also at the edge of the valence band. (C) 2001 Elsevier Science B.V. All rights reserved.