Dampfdruckmessungen und Protonenresonanzuntersuchung an Hydriden der intermetallischen Phasen Ti2(Ni,Co) und Ti2(Ni,Fe) |
| |
Authors: | Engelbert Tuscher Kurt Hiebl Helmut Bittner |
| |
Institution: | (1) Institut für Physikalische Chemie, Universität Wien, A-1090 Vienna, Austria |
| |
Abstract: | NMR and hydrogen equilibrium pressure measurements were performed on hydrides of the intermetallic compounds Ti2(Ni, Co) and Ti2(Ni, Fe). The following values of enthalpy H and entropy S for the formation of the hydrides of the intermetallic phases Ti2Co and Ti2Ni were found: H(Ti2CoH
y
)=–47.6 kJ/mol H2, H(Ti2NiH
y
)=–53.7 kJ/mol H2; S(Ti2CoH
y
)=–119.8 J/(K·mol H2), S(Ti2NiH
y
)=–127.5 J/(K·mol H2). By substitution of Ni or Co by Fe, the values of H and S of the corresponding quaternary hydrides become less negative. An interpretation of the experimental results is tried by the model ofShaltiel and coworkers.Proton diffusion was investigated in a series of the intermetallic hydrides Ti2(Ni, Co)H
x
and Ti2(Ni, Fe)H
x
. The diffusion rate is lowered by increased Ni/Fe substitution. Substitution of Ni by Co scarcely effects the hopping process . The activation energies were found to be smaller for the Ti2Ni-hydrides compared with the Ti2Co-hydrides.Herrn Prof. Dr.H. Nowotny zum 70. Geburtstag gewidmet. |
| |
Keywords: | Diffusion of hydrogen Hydrides of intermetallic compounds NMR Thermodynamic properties |
本文献已被 SpringerLink 等数据库收录! |
|