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 to 10² Ω^-1 cm^-1 if the density is increased from 2 to 6 g/cm³. 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/cm³. Conductivity data for dense gaseous mercurycesium mixtures are given.