Investigation Methods for The Determination of Thermodynamic Properties of Lithium Alloys

Abstract

The objective of thermodynamic investigations of alloys is the determination of the partial and integral Gibbs free energies of mixing ΔG, of the mixing enthalpies ΔH as well as of the mixing entropies ΔS, with their respective dependences on the concentration x, temperature T and pressure p, in correlation with the phase diagram. The three quantities of state quoted here are interconnected with each other by the Gibbs-Helmholtz relationship ΔG = ΔH − TΔS (1) and are defining the equilibrium state of an alloy at a given outer pressure. The enthalpies as well as the specific molar heats of a system can be directly obtained using calorimetric measuring methods whilst the partial Gibbs free energies as well as the integral Gibbs free energies, obtained herefrom by the Gibbs-Duhem integration, are directly accessible by EMF as well as by vapor pressure measurements.