Paramagnetic-Resonance Spectra of the3d5Configuration of Chromium in ZnSe and ZnTe

Paramagnetic-resonance measurements have been made for the $3d^5$ configuration of ${\mathrm{Cr}}^{+}$ in ZnSe and ZnTe. The $g$ factor, the cubic crystalline field parameter $a$, the hyperfine interaction with ${\mathrm{Cr}}^{53}$, $A\left({\mathrm{Cr}}^{53}\right)$, and the hyperfine interaction $A_{\mathrm{Zn}}$ with ${\mathrm{Zn}}^{67}$ nuclei occupying any of the twelve equivalent cation sites nearest the chromium have been determined. These resonance parameters are compared with those previously measured for ${\mathrm{Cr}}^{+}$ in cubic ZnS and CdTe and the variations from crystal to crystal are found to be consistent with changes in the covalency of the bonds and with lattice distortions caused by incorporating ${\mathrm{Cr}}^{+}$ substitutionally for the much smaller divalent zinc. The hyperfine interaction with ${\mathrm{Zn}}^{67}$ (or ${\mathrm{Cd}}^{111}$ and ${\mathrm{Cd}}^{113}$) at second-neighbor sites is, unlike the interaction of the isoelectronic ${\mathrm{Mn}}^{++}$ with these sites, found to vary from crystal to crystal in a manner consistent with changes in the covalent bonding.