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Raman scattering study of a phase transition in tantalum pentoxide
Author(s) -
Dobal P. S.,
Katiyar R. S.,
Jiang Y.,
Guo R.,
Bhalla A. S.
Publication year - 2000
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 - 10.1002/1097-4555(200012)31:12<1061::aid-jrs644>3.0.co;2-g
Subject(s) - tantalum pentoxide , raman spectroscopy , raman scattering , tantalum , phase transition , pentoxide , materials science , phase (matter) , x ray raman scattering , chemistry , chemical physics , analytical chemistry (journal) , optics , condensed matter physics , inorganic chemistry , physics , vanadium , organic chemistry , metallurgy
Ta 2 O 5 ceramics and crystals were prepared and analyzed using Raman spectroscopy in the temperature range 25–873 K. The low‐energy phonon bands (ν < 100 cm −1 ) of Ta 2 O 5 are assigned to external modes originating from the interaction between different Ta polyhedra and TaO n 5 − 2 n Ta 6 O 12 6+ clusters. The temperature and polarization dependence of external modes suggests the existence of clusters in the material. A softening of the low‐energy bands was observed with increasing temperature. The spectral evolutions show a soft mode‐derived second‐order monoclinic to orthorhombic phase transition at about 600 K in Ta 2 O 5 . Copyright © 2000 John Wiley & Sons, Ltd.