Nuclear Spin-Lattice Relaxation in Cadmium and Tin

Pulsed nuclear-magnetic-resonance measurements of the spin-lattice relaxation time $T_1$ in ${\mathrm{Cd}}^{113}$ and ${\mathrm{Sn}}^{119}$ from 77 to 820°K are reported. An enhancement of the Korringa product $T_{1}TK_{\mathrm{iso}}^{}{}_{}{}^2$ that is constant with temperature but different in the solid and liquid states is observed. For ${\mathrm{Cd}}^{113}$, the difference between the liquid and solid enhancement is significant and can be related to a core-polarization or orbital contribution to the isotropic Knight shift $K_{\mathrm{iso}}$. In solid ${\mathrm{Cd}}^{113}$, the sum of these two contributions to $K_{\mathrm{iso}}$ is about -9% as large as the contribution from the contact hyperfine interaction and that fraction is independent of temperature. In liquid ${\mathrm{Cd}}^{113}$ and solid and liquid ${\mathrm{Sn}}^{119}$, the sum of these contributions is probably small.