Numéro
J. Phys. Colloques
Volume 42, Numéro C5, Octobre 1981
ICIFUAS-7
Seventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
Page(s) C5-683 - C5-688
DOI https://doi.org/10.1051/jphyscol:19815105
ICIFUAS-7
Seventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids

J. Phys. Colloques 42 (1981) C5-683-C5-688

DOI: 10.1051/jphyscol:19815105

ULTRASONIC ABSORPTION IN SOME HIGHLY ATTENUATING IONIC-MOLECULAR CRYSTALS

F. Michard et F. Plicque

Laboratoire Dynamique Cristalline e t Uttrasons, D.R.P., Tour 22, Université Pierre et Marie Curie, 4, place Jussieu, 75230 Paris Cedex 05, France


Abstract
Unusually high values of the ultrasonic absorption observed at frequencies below 1 GHz in some ionic-molecular crystals the strontium, baryum and lead nitrates is a consequence of the existence of complex ions in the lattice. Acousto-optical interaction performed in the frequency range 0.1 GHz - 1 GHz and completed by data obtained at about 20 GHz by Brillouin scattering, allowed a very complete study from room temperature to 4 K of the dynamics of energy transfer between coupled internal and external vibrational modes in these compounds.