Theory of the Linear Electric Field Effect on the Electron-Paramagnetic-Resonance Spectra of3d5Ions in ZnS

Abstract

The linear effect of an external electric field on the EPR spectra of $d^5$ ions in cubic crystals is described by a third-rank tensor with only one independent component. The values of this parameter are calculated from a molecular-orbital theory for ${\mathrm{Cr}}^{+}$, ${\mathrm{Mn}}^{++}$, and ${\mathrm{Fe}}^{+++}$ in ZnS (zinc blende). Very good agreement with experiment is obtained by a mechanism in which charge-transfer levels and ligand orbitals play a dominant role.