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Low‐temperature order–disorder phase transition of PLZT x : 95:5 ceramics, with La Content x = 0.5–4% by weight, determined by Raman spectroscopy
Author(s) -
ElHarrad I.,
CarabatosNédelec C.,
Handerek J.,
Ujma Z.,
Dmytrow D.
Publication year - 1994
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1250251005
Subject(s) - raman spectroscopy , phase transition , analytical chemistry (journal) , materials science , atmospheric temperature range , ceramic , phase (matter) , softening , transition temperature , zirconate , population , spectral line , chemistry , condensed matter physics , thermodynamics , optics , physics , superconductivity , organic chemistry , chromatography , composite material , titanate , astronomy , demography , sociology
Investigations of the Raman spectra of lead–lanthanum–zirconate‐titanates (PLZT) x :95:5 ( x = 0.5, 1, 2, 3 and 4 wt.% La 2 O 3 ) ceramics over a range of temperature from 10 K to room temperature are presented. With increasing temperature the intensity of the Raman spectra, corrected for the Bose population factor, is lower above the transition temperature T 0 = 130 K; this intensity lowering is characteristic of disorder‐induced spectra. This temperature dependence is interpreted by means of the theory of fluctuating clusters in the low‐temperature phase and the order parameter below T 0 was determined. Associated with this phase transition, it was found that some softening effects are present in the vibrational wavenumbers.