Temperature-dependent Raman study of taurine single crystal

Polarized Raman spectra of an oriented taurine single crystal were studied at temperatures ranging from 7 to 300 K. The results show that several bands present a linewidth increase characteristic of anharmonic effects, and that the band related to the CSH torsional mode splits at low temperatures. An abrupt wavenumber jump of an external mode was associated with a phase transition undergone by the crystal between 250 and 260 K on cooling. A calorimetric investigation over the temperature range 173-308 K confirmed the existence of a first-order phase transition (at 251 K, on cooling), with a temperature hysteresis of 21 K. Copyright (C) 2001 John Wiley & Sons, Ltd.