Statistical thermodynamic characterization for hydrogen (H) absorption in quasi-crystalline Ti0.45Zr0.38Ni0.17 and amorphous Ti0.49Zr0.29Ni0.22Si0.09 alloys

Abstract Statistical thermodynamic characterization was attempted for equilibrium hydrogen (H) absorption data in quasi-crystalline Ti0.45Zr0.38Ni0.17-Hx and amorphous Ti0.49Zr0.29Ni0.22-Si0.09Hx alloys. H atom distribution patterns in these non-crystalline multi-component alloys appeared to vary depending on the range of composition x. The border compositions x distinguishing between H atoms distribution patterns appeared to be closely related to the atom fraction of metal constituents, Ti, Zr and Ni, in the metal sub-lattice. In the Ti0.49Zr0.29Ni0.22-Si0.09Hx alloy, Si atom in interstitial site appeared to act as preferential trapping site for H atoms (3 H atoms per each Si atom). This statistical model was somewhat similar to a statistical model proposed earlier for Th-CzHx in which interstitial C atom promoted H absorption by turning the state of surrounding interstitial sites being favorable for occupation with H atoms (3 sites per each C atom).