Changement de phase structural dans RbCdf3 et TlCdf3

M Rousseau , J.Y. Gesland , J. Julliard , J. Nouet , J. Zarembowitch , A. Zarembowitch

We have shown that a tetragonal distortion with c/a > 1 occurs at 124 K in RbCdF3 and at 191 K in TlCdF3. The anomalous behaviour of the elastic constant C44 is consistent with a slight rotation of the CdF6 octahedra. The study of both X-ray superstructure reflexions and Raman scattering spectrum allows us to retain the space group D184h for the low temperature phase. Two low frequency modes show the behaviour of soft modes.

Mots clés: elastic constants; Raman spectra of inorganic substances; rubidium compounds; solid state phase transformations; thallium compounds; X ray diffraction examination of materials; structural phase transition; fbcdf sub 3; tlcdf sub 3; tetragonal distortion; 124k; 191k; elastic constant; X ray superstructure reflections; raman scattering spectrum; space group; low temperature phase; low frequency modes; soft modes

Domaines: Articles anciens

M Rousseau, J.Y. Gesland, J. Julliard, J. Nouet, J. Zarembowitch, et al.. Changement de phase structural dans RbCdf3 et TlCdf3. Journal de Physique Lettres, 1975, 36 (5), pp.121-124. ⟨10.1051/jphyslet:01975003605012100⟩. ⟨jpa-00231168⟩