Partial atomic volume and partial molar enthalpy of formation of the 3d metals in the palladium-based solid solutions

Abstract

The composition dependence of the average atomic volume, as well as of the enthalpy of formation, was investigated for the palladium-containing binary systems with the 3d metals. The partial atomic volume and the partial molar enthalpy of formation of the 3d metals were determined for the palladium-based solid solutions (Pearson symbol cF4, space group $$Fm\bar 3m$$ , Cu type). The 3d early transition metals (scandium, titanium, and vanadium) as well as the 3d104s2 … 3d104s24p metals (zinc and gallium) show (1) the partial atomic volume for the palladium-based solid solutions smaller than is their atomic volume in the nonbonded state and (2) significantly large (negative) values of the partial molar enthalpy of formation indicating a strong bond energy between atoms of palladium and those of the 3d early transition metals (as well as a strong bond energy between atoms of palladium and zinc or gallium atoms). The 3d late transition metals (and chromium) show (1) the partial atomic volume for the palladium-based solid solutions larger than is their atomic volume in the nonbonded state and (2) low (negative) values of the partial molar enthalpy of formation indicating weak bond energy between atoms of palladium and those of the 3d late transition metals.