Neutron Scattering Study on the Incommensurate Phases in Ferroelectric Rb₂ZnCl₄ and K₂ZnCl₄

Abstract

The satellite reflections at (h, 0, l±(1⁄3−δ)) in Rb₂ZnCl₄ and K₂ZnCl₄ have been studied by neutron scattering. Incommensurate structures (δ≠0) were observed in temrerature ranges of +30°C∼−81°C for Rb₂ZnCl₄ and of +130°C∼+280°C for K₂ZnCl₄. The temperature dependence of the parameter δ was obtained for the two compounds and compared with the results of Rb₂ZnBr₄.