Electron Spin Resonance in Metals and Metal-Ammonia Solutions

Abstract

Electron spin resonance measurements have been made at 300 Mc/sec on frozen metal ammonia solutions, liquid metal ammonia solutions, and liquid metals. The experiments on frozen solutions have shown that the metal is precipitated out in small particles. Nuclear resonance experiments have corroborated this finding. The frozen solutions are used as a convenient source of small particles, and observations have been made of relaxation times in Na, Li, K, and Cs. Resonances in the liquid ammonia solutions of Li, Na, K, Rb, Cs, and Ca, and also in a solution of Li in methylamine were observed. The data are consistent with the theoretical model of Kraus, Ogg, and Kaplan and Kittel. Bulk metal resonances were observed to temperatures above the melting points on lithium and sodium. The results for sodium corroborate the Elliott theory of relaxation, and the lithium results indicate resistivity-dependent relaxation time. No resonance was observed in bulk K, Rb, and Cs carried to temperatures above their melting points.