Brillouin, Raman and light diffraction study of phase transitions in KLiSO4under a uniaxial stress

Abstract

The phase transitions between 150 and 300 K in KLiSO4 are studied under an applied stress through the simultaneous observation of Raman and Brillouin spectra and of the diffraction of light by the domain walls. Three distinct phases are identified; it is proved that between 190 and 265 K the sample can consist of the mixing of two phases; the ferroelastic behaviour of the low-temperature phase (T<190 K) is confirmed and the orientations of the related domain walls are defined.