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

Abstract

Abstract Amorphous and crystalline Ni 91 Zr 9 , and Cu 50 Zr 50 were exposed to gaseous hydrogen at pressures exceeding 1 GPa(H 2 ). The in situ measurements of relative electrical resistance and thermoelectric power as a function of hydrogen pressure were carried out for amorphous and crystalline Ni 91 Zr 9 samples. Similar measurements were not possible for Cu 50 Zr 50 alloys due to their brittleness caused by the hydrogen uptake. The change of electrical resistance for crystalline bcc Ni 91 Zr 9 samples clearly indicated the transformation into the hydride phase at hydrogen pressure near 0.67 GPa(H 2 ). The behaviour of the amorphous Ni 91 Zr 9 was different showing a continuous character of hydrogen absorption and desorption. The hydrogen absorption slightly reduced the initial positive value of thermoelectric power of both crystalline and amorphous alloys according to the general tendency observed for nickel alloyed with transition elements belonging to the left half of the transition group. The values of hydrogen concentration in the alloys exposed to the high hydrogen pressure are given.