Anomalous diffusion of Hydrogen in amorphous metals

Analysing the quasi-elastic neutron scattering from 8 at.% hydrogen in the metallic glass Ni24Zr76, we find that the hydrogen motion can be described in terms of anomalous diffusion. This process is analogous to that which leads to a strong frequency dependence of the conductivity in fast ionic conducting glasses. The data can be well described by an effective medium calculation based on a model with a broad distribution of activation energies. The same model can also successfully be applied to describe the anomalous temperature dependence of proton spin relaxation in amorphous metals