ISSN:
0377-0486
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Raman spectra of CsH2PO4 have been observed at 295 and 83 K in the frequency shift region 40-1200 cm-1. According to factor group analysis, Raman active vibrational modes at k = 0 are classified as follows; 13Ag + 8Bg in the paraelectric phase and 23A + 22B except for acoustic modes in the ferroelectric phase. No soft modes were observed in the A class modes. The frequency and the line width of one of the internal modes of the HPO42- ions were measured as a function of temperature in the scattering geometries b(cc)a* and c(bb)a*, where a* is perpendicular to the bc plane. Remarkable anisotropy was found in the temperature dependence of both the frequency and the line width. The results are discussed by considering that the phase transition is of an order-disorder type and the relaxation time of the polarization fluctuation is very long compared with the inverse of the associated phonon frequencies.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jrs.1250150206
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