Characterizing Phase Transitions in Liquid Cesium by a Soft-core and Large Attractive Equation of State

Abstract

This paper investigates to identify phase transitions in condensed liquid cesium metal by considering the variation of intermolecular potential parameters \epsilon and r_m in the whole liquid range, with \epsilon being the potential well-depth and r_m the position of minimum potential. These parameters were obtained from the parameters of a new equation of state that was derived recently by using the characteristic potential function. By this method, transitions at about 575 K, 800 K, 1000 K, 1350 K and 1650 K were identified. Transitions at 575 K, 800 K, and 1000 K are weak but, the one at 1350 K is very significant and has been explored experimentally and theoretically as the metal non-metal transition (MNMT), which is a phase transition before the critical condition dominates the thermodynamics. Also variations of the linear correlation coefficient of the isotherms generate a spot point pattern of these transitions. Our observations at 575 K for \epsilon and r_m are in accord with the anomalies in adiabatic thermal coefficient of pressure, density, viscosity, electrical conductivity, and structure factor.