Spin-Lattice Relaxation of Nuclei Due to Conduction Electrons at Very Low Temperatures

Formulas for the spin-lattice relaxation time of nuclei in metals at very low temperatures have been derived. The formulas show that the law ${\tau }_1\propto T^{-1\mathrm{}}$ holds only when $\mathrm{kT}\gg {\gamma }_n\hslash B$, whereas the relaxation becomes nonexponential (except in the case of $I=\frac{1}{2}$ and temperature-independent at lower temperatures.