Soft Manifold Dynamics Behind Negative Thermal Expansion

Abstract

Minimal models are developed to examine the origin of large negative thermal expansion (NTE) in under-constrained systems. The dynamics of these models reveals how underconstraint can organize a thermodynamically extensive manifold of low-energy modes which not only drives NTE but extends across the Brillioun zone. Mixing of twist and translation in the eigenvectors of these modes, for which in ZrW2O8 there is evidence from infrared and neutron scattering measurements, emerges naturally in our model as a signature of the dynamics of underconstraint.

5 pages, 3 figures

References in corpus (3)

• Low-temperature properties of classical, geometrically frustrated antiferromagnets
• Unusual Low-Energy Phonon Dynamics in the Negative Thermal Expansion Compound ZrW2O8
• Dynamics of some constrained lattices

Cited by in corpus (4)

• Entropic elasticity and negative thermal expansion in a simple cubic crystal
• Probing the Mott Physics in $\kappa$-(BEDT-TTF)${}_2$X Salts via Thermal Expansion
• Negative thermal expansion near two structural quantum phase transitions
• Negative thermal expansion near the precipice of structural stability in open perovskites