Local structure of metallic glasses as seen by mechanical hydrogen relaxation

As an application of hydrogen as a probe, the literature on the damping peak of hydrogen in about 30 amorphous alloys was examined with respect to the question of systematic structural differences between the different types of metallic glasses. A direct plot of measured peak temperatures, corrected to the same frequency, as a function of the peak height turned out to be most suitable for this purpose. Most of these data fall into a 40 K wide band, with no distinction between types like `metal_metalloidʹ, `metal_metalʹ, or `bulkʹ glasses. This general result suggests, in particular, that the outstanding thermal stability of bulk metallic glasses does not come from a specific amorphous structure. Stronger deviations from the general behaviour, as observed very clearly for Pd-based glasses and tentatively also for phase-separating systems, still need a closer examination.