Numéro
J. Phys. Colloques
Volume 42, Numéro C6, Décembre 1981
International Conference on Phonon Physics
Page(s) C6-602 - C6-604
DOI https://doi.org/10.1051/jphyscol:19816176
International Conference on Phonon Physics

J. Phys. Colloques 42 (1981) C6-602-C6-604

DOI: 10.1051/jphyscol:19816176

PHONON DISPERSION CURVES IN THE MOLECULAR CRYSTALS NAPHTHALENE AND ANTHRACENE MEASURED BY INELASTIC NEUTRON SCATTERING

B. Dorner1, E.L. Bokhenkov2, E.F. Sheka2, S.L. Chaplot3, G.S. Pawley3, J. Kalus4, U. Schmelzer4 et I. Natkaniec5

1  ILL Grenoble, France
2  Inst. Sol. Stat. Physics, Chernogolovka, USSR
3  Physics Dept. Univ . Edinburgh, U.K.
4  Physics Dept. Univ. Bayreuth, F.R.G.
5  Inst. Nucl. Phys. Krakow, Poland


Abstract
We determined the 12 external and the 4 lowest internal dispersion branches for several symmetry directions in naphthalene at 6 K and anthracene at 12 K. The zone centre modes have been assigned unambiguously. The temperature dependence was studied for both crystals, while the pressure dependence only for naphthalene. At constant volume the frequencies of naphthalene would increase much more with temperature than those of anthracene.