HYBRIDIZATION OF THE 3D STATES OF TRANSITION-METALS WITH THE STATES OF THE ZNS MATRIX

The near-edge soft x-ray absorption spectra of Zn1-xMxS compounds (whe re M is Mn, Fe, Co, and Ni, and x ranges to the solubility Limit) have been obtained by measuring the total electron yield (photoelectron, A uger and secondary) from the sample in an ultrahigh vacuum (UHV) sampl e chamber using x-rays from beam line 6.3.2, a bending magnet beamline at the Advanced Light Source (ALS). The high spectral resolution of t he beamline in the 50-1000 eV region allowed detailed measurements of S-L-2,L-3 and transition metal L-3 absorption spectra. The study of d and s antibonding states in Zn1-xMxS compounds provided evidence that 3d states of transition metals participate in the formation of ionic-c ovalence bonding between M-S. Furthermore, it was found that the abili ty of 3d electrons to participate in bonding decreases with increasing 3d orbit filling. As the 3d orbit becomes more closed, the 3d electro ns assume a more corelike character. The evidence of these behaviors c an be seen in the metal and sulfur L absorption spectra as well as in the charge transfer values calculated from the energy shifts in transi tion metal K edges. These findings provided an explanation for the dra stic decrease in the solubility of these particular metals in the ZnS matrix.