The Thermodynamic Characterization of ZrCo-H, HfCo-H, HfNi-H and Zr1-xHfxNi(Co) Alloy-H Systems

ZrCo and HfCo intermetallic compounds have the same cubic (CsCl-type) structure and their ternary (Zr1-xHfx)Co alloys are also cubic. ZrNi and HfNi intermetallic compounds have the orthorhombic structure (CrB-type) and the ternary (Zr1-xHfx)Ni alloys also have this structure. Thermodynamic data for hydride formation and decomposition in ZrCo, HfCo and HfNi intermetallic compounds have been determined from reaction calorimetry and from pressure-composition isotherms. Thermodynamic data have been determined for the three ternary alloys: (Zr0.75Hf0.25)Co, (Zr0.50Hf0.50)Co, and (Zr0.25Hf0.75)Co and the four ternary alloys: (Zr0.875Hf0.125)Ni, (Zr0.75Hf0.25)Ni, (Zr0.50Hf0.50)Ni, and (Zr0.25Hf0.75)Ni. This offers the opportunity to learn how the thermodynamic properties of the ternary alloy-H systems change with the stoichiometry of alloys with the same structure. (C) 2016 Elsevier B.V. All rights reserved.