Numéro
J. Phys. Colloques
Volume 42, Numéro C6, Décembre 1981
International Conference on Phonon Physics
Page(s) C6-785 - C6-787
DOI https://doi.org/10.1051/jphyscol:19816232
International Conference on Phonon Physics

J. Phys. Colloques 42 (1981) C6-785-C6-787

DOI: 10.1051/jphyscol:19816232

A RAMAN SCATTERING STUDY OF THE SOLID TO SOLID PHASE TRANSITION IN BENZIL

D.R. Moore1, V.J. Tekippe2, A.K. Ramdas3 et J.C. Toledano4

1  University of Illinois at Chicago Circle, U.S.A.
2  Gould Laboratories
3  Purdue University
4  C.N.E.T., France


Abstract
At 84° K, benzil undergoes a first order phase transition from D43 space group symmetry in the upper phase to C2 symmetry in the lower temperature phase with a simultaneous fourfold expansion of the primitive unit cell. In addition to the effects of the phase transition on the zone center optical modes which are Raman active above Tc, our polarized Raman studies do indeed show the emergence of new modes, including a second soft mode, which are related to the enlargement of the unit cell.