Metal-Nonmetal Transition in Dense Mercury Vapor

This article presents the results of conductivity and density measurements of liquid, gaseous, and supercritical mercury up to 1700°C and 2100 bar. Beyond the critical temperature of 1490°C the conductivity varies continuously from ${10}^{-4\mathrm{}}$ to ${10}^2$ ${\mathrm{\Omega }}^{-1\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$ if the density is increased from 2 to 6 g/${\mathrm{cm}}^3$. This variation is an example of nonmetal-metal transition and is discussed accordingly. The activation energy of conductivity in the supercritical fluid decreases markedly with increasing density and approaches very small values around 5 g/${\mathrm{cm}}^3$. Conductivity data for dense gaseous mercurycesium mixtures are given.