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Raman Scattering and X‐Ray Diffraction Study of a Phase Transition in (ND 4 ) 2 TeBr 6
Author(s) -
Shi J. R.,
Xu Y. C.,
Arnscheidt B.,
Pelzl J.,
Wu X.
Publication year - 1996
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/(sici)1097-4555(199609)27:9<691::aid-jrs21>3.0.co;2-6
Subject(s) - raman spectroscopy , tetragonal crystal system , laser linewidth , octahedron , diffraction , raman scattering , phase transition , crystallography , phase (matter) , chemistry , neutron diffraction , x ray crystallography , materials science , condensed matter physics , optics , crystal structure , physics , laser , organic chemistry
Raman spectra of (ND 4 ) 2 TeBr 6 were recorded in the temperature range 5–300 K. A continuous minimum of the Raman shift and a continuous maximum of the linewidth of the A 1 g mode of the TeBr 6 2− octahedron were observed at T c =68 K. Also, the T 2 g mode of the TeBr 6 2− octahedron continuously split into two lines below T c . X‐ray diffraction measurements at 10 K indicate that the low‐temperature phase has a primitive tetragonal structure, and an antiferro‐rotation of the TeBr 6 2− octahedra is associated with the transition. This behaviour indicates a displacive phase transition at T c .