Abstract
We report measurements of the thermal conductivity λ(T) of icosahedral in the temperature range 0.06–110 K. The quasilattice thermal conductivity increases monotonically with T in the temperature range between 0.06 and 25 K and above 55 K. A plateau is observed for (T) between 25 and 55 K, i.e., at substantially higher temperatures than in amorphous solids. Moreover, the thermal conductivity of icosahedral in the λ plateau region is substantially higher than that of insulating and metallic glasses. At lower temperatures, between 0.35 and 1.6 K, varies as . This (T) variation is compatible with a scattering of phonons by tunneling states. Below 0.35 K the thermal conductivity decreases with increasing slope suggestive of a crossover to a regime of excessive phonon scattering characterized by a temperature-independent mean free path.
- Received 9 September 1994
DOI:https://doi.org/10.1103/PhysRevB.51.153
©1995 American Physical Society