Pressure-induced phase transitions in antiferroelectric CsBi(MoO4)(2)
JOURNAL OF RAMAN SPECTROSCOPY, 36 (1):
56-62 (2005)DOI: 10.1002/jrs.1270
Abstract
The high-pressure Raman spectra of antiferroelectric CsBi(MoO4)(2) were
measured at room temperature. These studies indicated that this crystal
exhibits two pressure-induced phase transitions at 0.6 and 1.0 GPa. The
stable phase in the 0.6-1.0 GPa range was identified as having the same
structure as the ambient-pressure ferroelastic phase observed below 125
K. The transition at 1.0 GPa is connected with significant distortion of
the MoO42- tetrahedra and Bi3+ coordination sphere. The results suggest
that the phase above 1.0 GPa may have the same structure as the
high-pressure phase observed in KDy(MoO4)(2), KY(MoO4)(2) and
KTb(MoO4)(2) crystals. Upon releasing pressure, the high-pressure phase
transforms directly into the ambient-pressure phase. The origin of the
observed suppression of the intermediate phase is discussed. Copyright
(C) 2004 John Wiley Sons, Ltd.