Raman scattering study of LiKSO4—phases II and III

Detailed Raman scattering investigation of LiKSO₄ in phases II and III across the transition temperatureT _c ? 700 K is reported. Abrupt change in frequency and line width of the external and internal modes have been observed. Analysis of the results suggests lithium positional disorder and sulphate orientational disorder in the high temperature phase (II). The results also throw some light on the existence of twin domains in the crystal.