One-Dimensional Phonons and "Phase-Ordering" Phase Transition inHg3−δAsF6

Abstract

This paper reports elastic and inelastic neutron-scattering studies on the incommensurate linear-chain mercury compound ${\mathrm{Hg}}_{3-\delta }\mathrm{As}{\mathrm{F}}_6$. The one-dimensional phonon dispersion curve associated with the randomly phased linear Hg chains has been measured at room temperature. A transition, at 120 K, from a randomly phased interchain structure to a "phase-ordered" structure has been found and characterized.