Low temperature study of LiK1−xRbxSO4 mixed crystals

LiK 1−x Rb x SO 4 solid solutions have been obtained for different concentrations x. Crystals with x = 0.10 and 0.50 have been investigated by Raman spectroscopy, in the temperature range 80 - 300K. The room temperature spectra show that the sample with x = 0.10 crystallizes in the hexagonal P63 LiKSO4 structure, while the crystal with x = 0.50 probably presents a trigonal P31c structure. The low temperature measurements show an increase of the hexagonal - trigonal critical temperature and a decrease of the ferroelastic transition temperature with increasing Rb content.