Abstract
We have measured the internal friction and the Young's-modulus sound velocity at 1 kHz for . Below 20 K the relative change in the sound velocity and the temperature dependence of the internal friction perfectly resemble the behavior obtained for Suprasil W. Below 1 K we observe a logarithmic temperature dependence for the sound velocity and between 1 and 5 K a well-defined plateau in the internal friction is obtained. We find quantitative agreement with the predictions of the standard tunneling model which is widely used to explain the low-temperature properties of amorphous materials. The implications of the existence of tunneling systems in these materials are discussed.
- Received 21 August 1987
DOI:https://doi.org/10.1103/PhysRevB.37.545
©1988 American Physical Society