Croatica Chemica Acta, Vol. 61 No. 3, 1988.
Original scientific paper
Far Infrared Spectra, Phase Transitions, and Surface Layers
Armand Radni
; University of Nancy I, B. P. nO 239, 54506 Vandoeuvre les Nancy
Xavier Gerbaux
; University of Nancy I, B. P. nO 239, 54506 Vandoeuvre les Nancy
Abstract
Measurements of Far Infrared transmission for ferroelectric
plates of different thicknesses and orientations have suggested
for a few compounds that at 4 K the samples are not homogeneous
and can be described in a first approximation as having
an absorbing surface layer and a bulk nearly transparent in the
Far-Infrared. Amore detailed analysis suggests that the primitive unit-cell in the absorbing phase at low temperature is slightly modified
when it is displaced from the center, to the crystal surface. The structure cannot be described simply by the lattice translations applied to one unit-cell and is reminiscent of incommensurate structures.
Keywords
Hrčak ID:
175965
URI
Publication date:
30.11.1988.
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