Electron Correlation and Magnetism in Expanded Fluid Metals

Metals expanded by heating toward the liquid-gas critical point yield a remarkable low density metallic state before passing through a metal-nonmetal transition. Using high temperature-high pressure NMR techniques, we have investigated these low density metals with special concern for the behavior of the electronic density of states and spin fluctuations. The experiments reveal distinctly different properties for expanded monovalent metals (Cs) and divalent metals (Hg).