Accession Number : AD0764122

Title :   Thermal Conductivity of Germanium in the Boundary Scattering Regime.

Descriptive Note : Technical rept.,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF PHYSICS

Personal Author(s) : Campisi,George J.

Report Date : JUN 1973

Pagination or Media Count : 110

Abstract : Thermal conductivity measurements were made on high purity single crystals of germanium. Measurements on sandblasted polished samples were made in the temperature range of 1 to 4.2 K where isotope and boundary scattering are present. For samples with rough surfaces, the measured conductivity showed a strong dependence on the orientation of the rod axis and the width of the sample. The direction dependence of the conductivity, a consequence of the elastic anisotropy, was demonstrated when a sample with a (100) rod axis had a measured conductivity at 1.5K 45% higher than a sample with a (111) rod axis. A good fit to the measured conductivity data was obtained by using the Callaway theory that accounted for phonon-phonon scattering and for scattering from isotopic impurities and from rough ends and polished side surfaces. The Ziman theory of diffraction by surface irregularities in an infinitely long crystal was employed and it correctly predicted the temperature dependence of partial specular scattering. (Modified author abstract)

Descriptors :   (*GERMANIUM, THERMAL CONDUCTIVITY), SINGLE CRYSTALS, CRYOGENICS, SURFACE PROPERTIES, PHONONS, SCATTERING, THESES

Subject Categories : Solid State Physics
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE