Abstract
Thermal-conductivity measurements in solid in the bcc phase and at temperatures below about 0.5°K show an unexpected temperature dependence which is less than . Specific-heat measurements, in this temperature range, have been reported as showing a closely similar effect, and this provides evidence for a thermal excitation which must take part in the heat transport. In addition, Poiseuille flow of phonons has been directly observed.
- Received 21 October 1969
DOI:https://doi.org/10.1103/PhysRevLett.23.1330
©1969 American Physical Society