# Inelastic neutron scattering investigation of low temperature phase transition in Rb2ZnCl4 and K2ZnCl4

Inelastic neutron scattering investigation of low temperature phase transition in Rb2ZnCl4 and K2ZnCl4 - Download this document for free, or read online. Document in PDF available to download.

Abstract : Inelastic scattering of neutrons has revealed soft optic modes at the T point ${1}-{2}{\bf b}^*+{\bf c}^*$ of the Brillouin zone both in Rb2ZnCl4 and K2ZnCl4 which are responsible for the phase transition from the ferroelectric to the lowest temperature phase of these materials. Moreover, in K2ZnCl4 near the T point a minimum on the soft optic branch in the direction $\mu{\bf b}^*+ {1}-{2}{\bf c}^*$ has been found which confirms the existence of a new incommensurate phase recently discovered by Gesi. The origin of this incommensurate phase is discussed from a phenomenological point of view and formulae for elastic constants are derived describing their behaviour near transition into incommensurate phase.

Author: M. Quilichini V. Dvořák P. Boutrouille

Source: https://hal.archives-ouvertes.fr/