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Raman scattering study of phase transitions in undoped and rare earth ion‐doped BaCeO 3 and SrCeO 3
Author(s) -
Scherban T.,
Villeneuve R.,
Abello L.,
Lucazeau G.
Publication year - 1993
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.1250241114
Subject(s) - raman spectroscopy , tetragonal crystal system , raman scattering , analytical chemistry (journal) , doping , chemistry , phase transition , ion , dopant , atmospheric temperature range , praseodymium , crystallite , phase (matter) , perovskite (structure) , crystal structure , materials science , crystallography , condensed matter physics , inorganic chemistry , optics , physics , optoelectronics , organic chemistry , chromatography , meteorology
Polycrystalline samples of perovskite‐structured BaCeO 3 and SrCeO 3 were studied by Raman scattering spectroscopy in the temperature range 77–983 K. Changes in the spectra of BaCeO 3 with temperature are explained in terms of a second‐order phase transition ( D 2 h → D 4 h ) at T 0 = 427 K. Analysis of the temperature dependence of soft modes suggests a partial displacive character. A dramatic decrease in band intensity above 1000 K indicates a transition to the cubic ( O h ) structure, for which no Raman bands are expected. The Raman spectra of SrCeO 3 indicate that no phase transitions occur in the temperature range 77–983 K. Room temperature spectra of BaCeO 3 doped with various rare earth ions (Nd 3+ , Gd 3+ , Yb 3+ ) are compared. Doping with 5 and 10 mol.% Nd stabilizes the high‐temperature tetragonal and cubic phases, respectively. The crystal structure is a sensitive function of Nd dopant concentration.