Temperature variations of Raman internal modes in the CsDSO4 single crystal
were studied in the vicinity of superionic phase transition. Anomalous beh
aviour was observed 3 K below the superionic phase transition temperature T
-s. Within the same temperature range, new ferroelastic domains with (101)
walls were observed in the (010) surface of the crystal. The results point
to an existence either of a heterophase or a new phase in CsDSO4, in the te
mperature range T-s-3 K. (C) 2000 Elsevier Science B.V. All rights reserved
.