X-Ray Topographic and Polarisation-Optical Study of the Low-Temperature Phase Transitions and Domain Structures of KLiSO4

作者：Klapper H^*; Jennissen H D; Scherf Chr; Hahn Th

来源：Ferroelectrics, 2008, 376: 221-241.

DOI：10.1080/00150190802440724

• KLiSO4
• phase transitions
• domain structures
• X-ray topography
• polarisation optics

The transformations between the three polar low-temperature phases of KLiSO4 III (space group P63), IV (P31c) and V (C1c1 or P1121), were investigated by low-temperature X-ray topography and polarisation optics. The disappearance of the phase-III growth twinning (twin law m[001]) and the appearance of the phase-IV transformation twins (twin law 2 [001]) during the very sluggish III IV transition (ca. 225 K, thermal hysteresis 50 K) was directly observed. In both phases the domain boundaries are parallel (0001), normal to the polar axis [001] (pronounced memory effect). The III IV transition is strongly promoted by dislocations. The IV-V transition (190 K) shows the formation of three pseudo-hexagonal domains and the local metastable coexistence of phases III, IV and V. The ambiguities of the phase-V symmetry are discussed.

• 出版日期2008