Statistical Thermodynamics of Liquid Na–K Alloys

Abstract

A statistical thermodynamic calculation of liquid Na–K alloys using a generalized van der Waals theory is performed. The theory combining the Lebowitz equation for a hard-sphere mixture with an energy term showing the V^−1⁄3-dependence (V: volume) proves to be essentially successful to explain various thermodynamic properties (volume, enthalpy, entropy, concentration fluctuations, etc.) of the liquid alloys. The physical parameters (energy parameters, packing fraction, etc.) used in the calculation are determined by solving the equation of state directly. Structure factors calculated are found to reproduce well observed data. Some critical discussions about other theories are made.