Dynamic Disorder in Negative Thermal Expansion Compound Zn(CN)2

TL;DR

This study investigates the dynamical disorder in Zn(CN)2, a negative thermal expansion material, using quasielastic neutron scattering to analyze CN reorientation and its temperature dependence.

Contribution

It provides the first detailed analysis of CN reorientation dynamics in Zn(CN)2 across a range of temperatures using neutron scattering.

Findings

Quasielastic broadening appears above 250 K

CN reorientation times are 16 ps at 270 K and 11 ps at 320 K

No broadening observed below 220 K

Abstract

Dynamical disorder in negative thermal expansion compound Zn(CN)2 is investigated by quasielastic neutron scattering technique in the temperature range 170-320 K. Significant quasielastic broadening is observed above the phase transition temperature of about 250 K, however no broadening is observed at 220 K and below. Data at high temperatures are analyzed assuming the CN reorientation. Characteristic time associated with the CN orientation is estimated as 16 ps and 11 ps at 270 and 320 K respectively.