Ultrasound velocity in neutron‐irradiated quartz crystals above 5 K

A linear temperature dependence of the sound velocity above 5 K is a universal property for amorphous and disordered solids. However, there are several theoretical models, which propose the explaination of this universal behaviour at intermediate temperatures. Previous low-temperature measurements have shown that the neutron-irradiated quartz can be used for the study of the glassy dynamics. In this paper we present the results of the ultrasound velocity measurements in neutron-irradiated quartz crystals at temperatures 5–35 K and discuss them in the framework of the different models. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)