Strain-Induced Zero-Field Splitting ofd3andd8Ions in Cubic Crystals

Abstract

The zero-field splitting of ions with $d^3$ and $d^8$ electron configurations is calculated by the perturbation theory. We consider the ionic and covalent contributions and that of anisotropic spin—spin coupling due to covalency effects. For comparison with experiment, the numerical values for ${\mathrm{V}}^{2+}$, ${\mathrm{Cr}}^{3+}$, and ${\mathrm{Ni}}^{2+}$ ions in uniaxially stressed MgO crystals are estimated.