High Temperature Thermodynamics of Solutions of Hydrogen and Deuterium in Palladium and its Alloys

Abstract

AbstractThe solutions of hydrogen in palladium and its alloys are classical examples of interstitial metallic solutions. Although these alloys have been studied for a very long time, a good deal of new information has become available in recent years, partly as a result of the application of the combined calorimetric‐equilibrium approach. This experimental method, which was developed in our laboratory about 10 years ago, allows essentially simultaneous determinations of the Gibbs energies, the enthalpies and the entropies of solution. This approach has been particularly useful in throwing new light on the temperature dependence of the thermodynamic properties, and also on their dependence on the alloying constituents. Special interest is attached to the new information on the partial entropies of hydrogen, which points strongly toward a temperature dependent, non‐random distribution of the hydrogen atoms among the available interstitial sites.