| Numéro |
J. Phys. Colloques
Volume 42, Numéro C5, Octobre 1981
ICIFUAS-7Seventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids |
|
|---|---|---|
| Page(s) | C5-587 - C5-591 | |
| DOI | https://doi.org/10.1051/jphyscol:1981590 | |
ICIFUAS-7
Seventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
J. Phys. Colloques 42 (1981) C5-587-C5-591
DOI: 10.1051/jphyscol:1981590
1 Institute of Electro-optical Engineering, National Chiao-Tung, University Hsinchu, Taiwan, China
2 Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, U.S.A.
Seventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
J. Phys. Colloques 42 (1981) C5-587-C5-591
DOI: 10.1051/jphyscol:1981590
ULTRASONIC PROPAGATION IN THE LIQUID CRYSTAL PHASES OF P-ALKOXYBENZOIC ACIDS
L.S. Chou1 et S.V. Letcher21 Institute of Electro-optical Engineering, National Chiao-Tung, University Hsinchu, Taiwan, China
2 Department of Physics, University of Rhode Island, Kingston, Rhode Island 02881, U.S.A.
Abstract
Ultrasonic absorption has been measured in p-alkoxybenzoic acids in the isotropic, nematic and smectic phases in the the frequency range 9-85 MHz. The frequency and temperature dependence of the absorption indicates the presence of relaxation processes, which are attributed to rearrangements of the equilibrium distributions of open dimers and cyclic dimers. The relaxation frequency is about 15 MHz in the nematic phase.