抄録
The structural phase transition of a linear chain compound (CH3)3NHCdCl3 (TrMCC) was studied by X-ray diffraction method. Accompanying the phase transition from the (1×\sqrt3) structure to the (2×\sqrt3) structure, strong diffuse streaks were observed along the b* direction. In order to explain the observed peak profiles, a simplified model was presented. In this model, the layers made of rather tightly coupled CdCl3 chains were assumed to stack with probabilities. The diffraction intensity was analyzed using the matrix method given by Kakinoki and Komura. The calculation which incorporates the effect of the phase shift due to the displacements normal to the stacking direction was found to reproduce the experimental results fairly well. The streaks observed in the (3×2) phase were also discussed.
