| Numéro |
J. Phys. Colloques
Volume 42, Numéro C5, Octobre 1981
ICIFUAS-7Seventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids |
|
|---|---|---|
| Page(s) | C5-855 - C5-866 | |
| DOI | https://doi.org/10.1051/jphyscol:19815133 | |
ICIFUAS-7
Seventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
J. Phys. Colloques 42 (1981) C5-855-C5-866
DOI: 10.1051/jphyscol:19815133
Department of Physics and Metals Research Laboratory, Brown University, Providence, R.I. 02912, U.S.A.
Seventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
J. Phys. Colloques 42 (1981) C5-855-C5-866
DOI: 10.1051/jphyscol:19815133
ULTRASONIC STUDIES OF PHASE TRANSITIONS
C. ElbaumDepartment of Physics and Metals Research Laboratory, Brown University, Providence, R.I. 02912, U.S.A.
Abstract
Ultrasonic studies of phase transitions and of some related phenomena in various systems are briefly reviewed. The responses of high frequency (ultrasonic) stress waves to order parameter changes and to pretransitional fluctuations are discussed. Emphasis is given to recent investigations of anharmonic effects in ultrasonic propagation near the lambda transition of liquid helium, as a prototypical example of the role played by nonlinear properties. In particular, experimental results are reviewed on the diverging behavior of the anharmonic coupling coefficient between the fundamental wave and its second harmonic, as the transition temperature is approached.