Phonon Scattering by Isolated Isotopic Impurities in Single Crystals of Helium.
Abstract
Thermal conductivity measurements of oriented single crystals of hexagonal close-packed He4 have been made in order to study the scattering of phonons by isotopic impurities. Apparatus and techniques have been developed which allow the growth of crystals at preferred orientations: c-axis orientations of 0 and 90 degrees with respect to the direction of heat flow were chosen for this study. Quality and orientation of the sample crystals were determined from the thermal conductivity measurements themselves. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1971
- Accession Number
- AD0734171
Entities
People
- Dewey Tull Lawson
Organizations
- Duke University