X-Ray Diffraction Study of the Structures of Normal and Ferroelectric [N (CH₃)₄]₂ZnCl₄

Abstract

The crystal structure of [N (CH 3 ) 4 ] 2 ZnCl 4 was studied at three temperatures, 30, 60and 90°C, in the paraelectric phase and at 5.5°C in the ferroelectric phase by using theX-ray reflection data collected by an automatic four-circle diffractometer. The split-atom method and the significance test showed that the constituent ions are in disorder in the normal phase. In the ferroelectric phase, positional and thermal parameters and occupation probability of ions were calculated by the least-squares method. The density modulation of ZnCl 4 and that of one kind of N(CH 3 ) 4 ion were closely incorporated.