| Numéro |
J. Phys. Colloques
Volume 33, Numéro C4, Octobre 1972
COLLOQUE INTERNATIONAL DU C. N. R. S. SUR LA PHYSIQUE DES PHONONS DE TRÈS HAUTE FRÉQUENCE / ON THE PHYSICS OF VERY HIGH FREQUENCY PHONONS
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| Page(s) | C4-1 - C4-1 | |
| DOI | https://doi.org/10.1051/jphyscol:1972401 | |
J. Phys. Colloques 33 (1972) C4-1-C4-1
DOI: 10.1051/jphyscol:1972401
GENERAL INTRODUCTORY SESSION
TECHNIQUES AND RESULTS OF HEAT PULSE EXPERIMENTS
R. J. VON GUTFELD IBM Thomas J. Watson Research Center Yorktown Heights, New York 10598
Abstract
A general review of experimental heat pulse techniques with interpretations of some typical data is given. Several heat pulse generators are described including thin films utilizing pulsed currents, tunnel junctions and superconducting films in which the down-conversion of high frequency phonons occurs. The black body radiation model will be reviewed and related to the temperature of the pulsed current generator and the resulting phonon propagation. A brief review of heat pulse detectors will be given in order to characterize their properties as a function of temperature and magnetic field. Results of heat pulse experiments will be presented by interpreting several portions of some detected heat pulse signals including [1] the ballistic region and the relation between the energy and phase velocities [2], the second sound regime (if any) and its relation to normal and umklapp scattering rates [3], the scattered or diffusive portions and their relation to crystal defects and phonon polarization. Of the specific examples of scattering to be discussed, emphasis will be on phonon scattering in Ge due to donor impurities.