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Direct Observation of Entropic Stabilization of bcc Crystals Near Melting

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Sprakel, J 
Zaccone, A 
Spaepen, F 
Schall, P 
Weitz, DA 

Abstract

Crystals with low latent heat are predicted to melt from an entropically stabilized body-centered cubic symmetry. At this weakly first-order transition, strongly correlated fluctuations are expected to emerge, which could change the nature of the transition. Here we show how large fluctuations stabilize bcc crystals formed from charged colloids, giving rise to strongly power-law correlated heterogeneous dynamics. Moreover, we find that significant nonaffine particle displacements lead to a vanishing of the nonaffine shear modulus at the transition. We interpret these observations by reformulating the Born-Huang theory to account for nonaffinity, illustrating a scenario of ordered solids reaching a state where classical lattice dynamics fail.

Description

Keywords

cond-mat.soft, cond-mat.soft, cond-mat.mtrl-sci

Journal Title

Physical Review Letters

Conference Name

Journal ISSN

0031-9007
1079-7114

Volume Title

118

Publisher

American Physical Society
Sponsorship
This work was supported by the National Science Foundation (DMR-1310266, DMR-1206765), the Harvard Materials Research Science and Engineering Center (DMR-1420570), and NASA (NNX13AQ48G).