Premium
Raman spectroscopic studies on sodium metavanadate
Author(s) -
Seetharaman S.,
Bhat H. L.,
Narayanan P. S.
Publication year - 1983
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.1250140608
Subject(s) - raman spectroscopy , ferroelectricity , phase transition , dielectric , crystallography , chemistry , phase (matter) , materials science , analytical chemistry (journal) , condensed matter physics , optics , organic chemistry , physics , optoelectronics
Sodium metavanadate (NaVO 3 ) has been reported earlier to exhibit ferroelectric behaviour below 380 °C, but unlike many other known ferroelectrics it does not show a very strong dielectric anomaly, indicating that the structural change during the ferroelectric phase transition may be only a slight modification of the paraelectric phase. This is in conformity with the x‐ray data at room temperature, which could be refined to the same R value either in space group C2/c or Cc. Further, it is known that NaVO 3 occurs also in another polymorphic modification (β‐form), the structure of which has not been established. Raman spectroscopic studies of single crystals of the α‐form of NaVO 3 have been carried out and a crystalline powder of the β‐form has been made. The Raman spectra have been interpreted in terms of the linear VO 3 −chains formed by VO 4 tetrahedra sharing two corners with each other. The temperature variation of the intensity and width of the Raman lines through the phase transition has been measured and the observed LOTO splitting in the room temperature phase confirm the Ce ferroelectric space group.