Mechanical spectroscopy of hydrogen-absorbing quasicrystals

The H-induced damping peak in icosahedral quasicrystals, generally attributed to a Snoek-type reorientation mechanism, was studied in comparison between Zr69.5Cu12Ni11Al7.5 and Ti53Zr27Ni20 using the vibrating-reed technique. Whereas the peak in Zr69.5Cu12Ni11Al7.5 is practically the same as in the amorphous phase (in accordance with icosahedral short-range order in metallic glasses), significant differences in shape and position of the peak are found between the two quasicrystalline alloys. These might possibly be used as a probe to distinguish between icosahedral structure types. Another interesting result is a higher intrinsic damping of quasicrystalline Zr69.5Cu12Ni11Al7.5, compared to the amorphous phase, between 450 and 650 K.