Absorption of hydrogen in Zr based amorphous alloys under high pressures of gaseous hydrogen

摘要

Amorphous and crystalline Ni_91Zr_9, andCu_50Zr_50were exposed to gaseous hydrogen at pressuresexceeding 1 GPa (H_2). The in situ measurements of relativeelectrical resistance and thermoelectric power and a function ofhydrogen pressure were carried out for amorphous and crystallineNi_91Zr_9 samples. Similar measuements wre not possible forCu_50Zr_50 alloys due to their brittleness caused by the hydrogenuptake. The change of electrical resistance for crystalline bccNi_91Zr_9 samples clearly indicated the transformation into thehydride phase at hydrogen pressure near 0.67 GPa (H_2). Thebehaviour of the amorphous Ni_91Zr_9 was different showing acontinuous character of hydrogen absorption and desorption. Thehydrogen absorption slightly reduced the initial positive value ofthermoelectric power of both crystalline and amorphous alloysaccording to the general tendency observed for nickel alloyed withtransition elements belonging to the left half of the transitiongroup. The values of hydrogen concentration in the alloys exposedto the high hydrogen pressure are given. 1999 Elsevier Science S.A.All rights reserved.