H-induced anelasticity as a probe: Application to nanoscale quasicrystals

Hydrogen-Induced Damping Peak Temperatures in Bulk Metallic Glasses

“…Also the assumed detrimental effect of asymmetric two-level systems on the strength of the Snoek-type relaxation [4] is possibly strongly overestimated: as a consequence of a well-developed icosahedral short-range order, as indicated by the quantitative agreement of the hydrogen peak between amorphous and quasicrystalline phases (see [5][6][7][8][9][10] for more details), the two-level systems may in fact be much more symmetric at least in the case of quasicrystal-forming bulk metallic glasses.…”

“…For part of these alloys (the Ti-Zr-Ni quasicrystals and Zr 69.5 Cu 12 Ni 11 Al 7.5 ), the H-induced damping spectra could be used from the previous work [6][7][8][9][10]. The spectra of the remaining alloys were obtained in the same way: as described in more detail elsewhere (e.g., (6,16]), the resonance frequency f and internal friction Q -1 of flexural vibrations of clamped cantilever-type samples were measured as a function of temperature (heating rate 2 K/min) by a standard vibrating-reed technique.…”

“…It was pointed out in a more general context that because of the polytetrahedral character of amorphous as well as of icosahedral quasicrystalline structures, a Snoek-type reorientation mechanism should generally be expected for the anelastic relaxation of hydrogen in all these cases [5]. Related experimental work on quasicrystals and on amorphousquasicrystalline transitions has recently been published in several papers [6][7][8][9][10]. In the present contribution, the aspect of icosahedral order and quasicrystal formation is introduced more specifically into the discussion of H-induced damping in amorphous alloys, using comparative T p (Q p -1 ) plots and considering the implications for the relaxation mechanism.…”