Numéro
J. Phys. Colloques
Volume 42, Numéro C6, Décembre 1981
International Conference on Phonon Physics
Page(s) C6-415 - C6-417
DOI https://doi.org/10.1051/jphyscol:19816121
International Conference on Phonon Physics

J. Phys. Colloques 42 (1981) C6-415-C6-417

DOI: 10.1051/jphyscol:19816121

ROLE OF POLAR PHONONS IN THE CHEMICAL BOUND AT STRUCTURAL PHASE TRANSITIONS CHARACTERIZED BY REPETITIVE FOURIER SPECTROSCOPY

F. Gervais1 et J.L. Servoin2

1  Centre de Recherches sur la Physique des Hautes Températures, C.N.R.S., 45045 Orléans, France
2  Centre de Recherches sur la Physique des Hautes Températures, C. N. R. S., 45045 Orléans, France


Abstract
The temperature dependence of dynamic effective charges carried by Ti and Nb ions which are the movable atoms involved in the ferroelectric phase transition of BaTiO3 and KNbO3, respectively, are reported, as deduced from TO-LO splittings of polar lattice modes, including soft modes. Results below the semiconducting-metal phase transition of NbO2 are also discussed.