Resonant ultrasound spectroscopy has been used for the measurement of the elastic moduli of a Ti-based quasicrystal, one of the major classes of quasicrystals. Both the bulk and shear elastic moduli of a Ti-Zr-Ni multigrained icosahedral quasicrystal and a polycrystalline 1/1 approximant were measured over the temperature range of 15–300 K. The elastic moduli of these two materials are very nearly the same, a result in agreement with the belief that the structures of these two materials are closely related. The temperature dependence of the moduli resembles that of ordinary metals. The results have been used to predict the acoustic contribution to the low-temperature specific heat. This contribution is much larger in these Ti-based materials than for the Al-based quasicrystals reported by others. Besides their general interest, the elastic moduli are useful for constructing atomic potentials in these unusual materials.

• Received 6 October 1998

DOI:https://doi.org/10.1103/PhysRevB.59.11132