DSC, DTA and TG studies on structural phase transitions in Tl2ZnCl4

Abstract Among A 2 BX 4 -type compounds belonging to the pseudo-hexagonal β-K 2 SO 4 structure known to form incommensurate (IC) phases at low temperatures, the phase transition sequence in Tl 2 ZnCl 4 , where Rb + ions in the representative compound Rb 2 ZnCl 4 were substituted by Tl + ions with a similar ionic radius, was investigated by the differential thermal analysis (DTA) and the differential scanning calorimetry (DSC). The composition of a hydrous compound which was obtained by keeping under the atmosphere was determined to be Tl 2 ZnCl 4 ·1.5H 2 O by the thermogravimetric (TG) analysis.