Short-time dynamics on a metallic glass as probed by deep inelastic neutron scattering

We report on deep inelastic neutron scattering (DINS) measurements on amorphous and crystalline Ni0.83B0.17 alloys, at temperatures of 30, 150 and 300 K. From the observed differences in the neutron Compton profile (NCP), it is found that the kinetic energy of the glassy state is systematically Lower than that of the corresponding crystal. The origin of such a difference can be traced down to the generalized frequency distributions which make the particle embedded in a glassy or crystal matrix to experience significantly different effective temperatures than those within the ordered phase.