research papers
Image contrast of domains and discommensurations in ferroelectric Rb2ZnCl4 is studied. Six domains of the two orientation variants and three translation variants in the ferroelectric phase are observed. However, only two kinds of domain boundaries, which are the discommensurations in the incommensurate phase of Rb2ZnCl4, are observed. These observations agree with group-theoretical considerations of the phase transition from the normal phase to the commensurate phase of Rb2ZnCl4.