Nuclear Spin Relaxation in Cs Metal

The characteristic nuclear-magnetic-resonance parameters, Knight shift, line shape and width, and relaxation times have been measured in cesium metal from the melting point to 1.6^∘{}K. The nuclear spin relaxation time T₁ is inversely proportional to the temperature from 300 to 7^∘{}K, with T₁T=0.135±0.01 sec ^∘{}K. For temperatures below 7^∘{}K, the relaxation shows another contribution of unknown origin. The Knight shift increases linearly with temperature down to 4^∘{}K, following the line previously measured by Gutowsky and McGarvey at higher temperatures. Diffusion narrowing of the magnetic-resonance line is observed at 190^∘{}K, but the strong electron-nucleus interactions preclude good diffusion-constant measurements.