Influence of the hydrogen content on hydrogen diffusion in the Zr69.5Cu12Ni11Al7.5 metallic glass

We present a study of the temperature- and concentration-dependent hydrogen self-diffusion constant D in a Zr69.5Cu12Ni11Al7.5 metallic glass using the technique of nuclear magnetic resonance diffusion in a static fringe field of a superconducting magnet. In the investigated temperature interval between room temperature and 420 K, D is in the range 10−8-10−9 cm2/s and obeys Arrhenius form, D=D0exp(−Ea/kBT), indicating classical over-barrier-hopping hydrogen diffusion with an activation energy Ea. The concentration dependence of Ea and D was studied for the hydrogen-to-metal ratio H/M between 0 and 1.9. At low hydrogen content, H/M<0.2, Ea shows no noticeable concentration dependence, whereas D exhibits a weakly pronounced maximum at H/M=0.1 In the intermediate concentration regime, 0.2