Liquid Phase Metal-Non Metal Transition In Carbon

Abstract

It is proposed that the liquid phase metal-non metal transition in carbon takes place between an sp hybridized non-metallic liquid, with coordination number two, and a strongly correlated liquid metal in which directional bonding remains important though the hybridization and coordination number will probably change. Only at higher pressures is a quadrivalent liquid metal carbon to be expected, the formation of which should occur at the known maximum in the melting line of graphite. Motivated by a phenomenological argument, possible experiments to clarify the nature of these different liquid phases are proposed.