Enthaply of hydrogen in palladium alloys at constant interstitial volume

Abstract

The enthalpy of hydrogen at infinite dilution in palladium alloys has been calculated using a model in which the interstitial volume available to hydrogen atoms is kept constant. Under these conditions it is found that alloying elements are divided into two groups. Transition elements increase the enthalpy and non-transition elements decrease the enthalpy of hydrogen relative to palladium. These results are interpreted in terms of variations in the localised electronic properties of palladium atoms due to interactions with nerest neighbour metal atom additives.