title: Direct Observation of Entropic Stabilization of bcc Crystals Near Melting.
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.
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.|Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.|Physical Chemistry and Soft Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
authors.forename: Joris
authors.initials: J
authors.lastname: Sprakel
authors.affiliation: Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, CB2 3RA Cambridge, United Kingdom.
authors.forename: Alessio
authors.initials: A
authors.lastname: Zaccone
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Frans
authors.initials: F
authors.lastname: Spaepen
authors.affiliation: Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: Schall
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.|Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Weitz