Internal friction studies by resonant ultrasound spectroscopy

A description is given of the use of resonant ultrasound spectroscopy (RUS) to study internal friction in solids. The technique is applicable to a wide range of sample sizes and shapes. A method to extract the internal friction from the RUS spectrum in the presence of a coherent background signal is discussed. RUS has been used to study the internal friction due to hydrogen motion in hydrogen–metal materials. A comparison is made of internal friction due to hydrogen motion in a C15 Laves-phase intermetallic compound with that in a quasicrystalline material. The internal friction peak in the quasicrystalline material is much broader, probably reflecting a distribution of local environments for the hydrogen in this material. A low-temperature, internal friction peak due to deuterium motion in TaV2D0.17 is discussed. This peak was shown previously to result from a rapid local motion of D on a hexagon of interstitial g sites. A novel explanation is proposed for the temperature dependence of this peak.