Acoustical-Paramagnetic-Resonance Study ofV3+Ions in Corundum

An experimental and theoretical acoustical-paramagnetic-resonance study has been made on $3d^2$ ions (${\mathrm{V}}^{3+}$ and ${\mathrm{Cr}}^{4+}$) in corundum. The hyperfine structure of ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}_{}^{3+}{}_{}{}^{}$ ions is resolved and supplementary lines are explained by both electronic and nuclear transitions ($\Delta M=2\mathrm{}$, $\Delta m=1\mathrm{}$). Some combinations of coupling constants of ${\mathrm{V}}^{3+}$ have been measured: ${(\frac{1}{4}{G_{-}}^2+{G_{16}}^2)}^{\frac{1}{2}}=140\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$, ${({G_{14}}^2+{G_{15}}^2)}^{\frac{1}{2}}=130\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$. Results from $\gamma$-irradiated ruby show that ${(\frac{1}{4}{G_{-}}^2+{G_{16}}^2)}^{\frac{1}{2}}>60\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$ for the ${\mathrm{Cr}}^{4+}$ ion.