Relationship between the time-dependent specific heat and the ultrasonic properties of glasses at low temperatures
- 15 March 1978
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 17 (6), 2740-2761
- https://doi.org/10.1103/physrevb.17.2740
Abstract
We explore the issue of whether the tunneling model proposed by Anderson, Halperin, and Varma and by Phillips can explain both the time-dependent specific-heat experiments and the ultrasonic experiments on glasses at low temperatures. In addition, we consider the possibility that there may be two types of tunneling levels, "standard" and "anomalous," with the latter contributing only to the specific heat. Using ultrasonically determined parameters, we make theoretical predictions for the long-time and short-time specific heat of fused silica, based upon a corrected version of the coupled-Boltzmann-equation formalism of Heinrichs and Kumar. These predictions are compared with the heat-pulse experiments of Goubau and Tait, which indicate that the short-time specific heat is a large fraction of the long-time specific heat. Based on standard levels alone, our predictions for the specific heat at both long and short times are significantly smaller than the experimental results. With both standard and anomalous levels present, the theory agrees with experiment at long times, but the theoretical specific heat is still too small at short times. This short-time discrepancy raises the fundamental question of whether the heat-pulse results are consistent with ultrasonically determined phonon-scattering rates.Keywords
This publication has 32 references indexed in Scilit:
- THE ANOMALOUS THERMAL PROPERTIES OF GLASSES AT LOW TEMPERATURES*Annals of the New York Academy of Sciences, 1976
- Thermal conduction in glasses and polymers at low temperaturesJournal of Physics C: Solid State Physics, 1974
- Random-network model, density fluctuation, and thermal conductivity of glassesSolid State Communications, 1974
- Low-Temperature Specific Heat and Thermal Conductivity of Noncrystalline Dielectric SolidsPhysical Review B, 1973
- A cellular model for the specific heat of amorphous solids at low temperaturesSolid State Communications, 1973
- Frequency Spectrum and Low-Temperature Specific Heat of Noncrystalline SolidsProgress of Theoretical Physics, 1972
- Tunneling states in amorphous solidsJournal of Low Temperature Physics, 1972
- Anomalous low-temperature thermal properties of glasses and spin glassesPhilosophical Magazine, 1972
- Low-Temperature Specific Heat and Thermal Conductivity of Noncrystalline SolidsPhysical Review Letters, 1971
- Thermal Conductivity and Specific Heat of Noncrystalline SolidsPhysical Review B, 1971