Study of thermal disordering of the KSc(WO4)2 crystal structure by Raman spectroscopy

Raman spectra of KSc(WO4)2, exhibiting three reversible phase transitions from a trigonal phase to monoclinic and triclinic structures, have been studied in the temperature region of 100-294 K. The mea surements have revealed the presence of significant broadening of librational and translational modes of the WO2 4 ions with increasing temperature. This broadening was explained as a result of anisotropic activation of the complex ion reorientations.