Ultrasonic attenuation measurements were performed, at 35 to 335K, on a multi-grained icosahedral quasicrystal and a 1/1 body-centered cubic polycrystalline approximant. The alloys were hydrogenated so as to give a H/metal ratio of 0.79 for the icosahedral phase and 0.20 for the crystalline phase. Temperature-dependent attenuation peaks were observed in alloys which were loaded with H, while H-free materials exhibited no unusual features. For measurement frequencies which were near to 1MHz, the attenuation maxima occurred near to 250K in the crystalline phase and near to 220K in the icosahedral phase. The results implied that H motion was about an order of magnitude faster in the icosahedral phase than in the approximant phase. It remained unclear whether this was due to an intrinsic difference between the 2 phases or was due to a dependence upon the H concentration.

Ultrasonic Study of Hydrogen Motion in a Ti-Zr-Ni Icosahedral Quasicrystal and a 1/1 BCC Crystal Approximant. K.Foster, R.G.Leisure, J.B.Shaklee, J.Y.Kim, K.F.Kelton: Physical Review B, 2000, 61[1], 241-5