Nuclear Spin Relaxation in Gallium Metal

The nuclear spin-lattice relaxation time T₁ has been measured in a fine powder of gallium metal from near the superconductivity transition temperature 1.1^∘{}K to near the melting point 307^∘{}K. The experiments were performed with pure nuclear quadrupole resonance using pulsed-nuclear-resonance techniques. Between approximately 4.2 and 300^∘{}K the product of T₁ and the absolute temperature is found to be temperature-dependent, varying from 1.01 sec^∘{}K between 1.1 and 4.2^∘{}K to 0.73 sec^∘{}K at 300^∘{}K. The relaxation mechanism is magnetic in origin, as determined from the ratio of the relaxation times for the Ga⁶⁹ and Ga⁷¹ nuclei. Various explanations for the temperature dependence of T₁T are discussed.