Pressure-induced softening as a common feature of framework structures that have negative thermal expansion

TL;DR

This study uses molecular dynamics simulations to show that pressure-induced softening is likely common in framework materials with negative thermal expansion, highlighting a thermodynamic correlation between the two phenomena.

Contribution

It reveals that pressure-induced softening is a widespread feature in framework materials exhibiting negative thermal expansion, supported by thermodynamic analysis.

Findings

Pressure-induced softening observed in cubic siliceous zeolites

Correlation between negative thermal expansion and softening

Thermodynamic basis for the phenomena

Abstract

Results of a series of molecular dynamics simulations of cubic siliceous zeolites suggest that pressure-induced softening -- the phenomenon in which a material becomes progressively more compressible under pressure -- is likely to be a common feature of framework materials that show negative thermal expansion. The correlation between the negative thermal expansion and the pressure-induced softening is investigated on the basis of thermodynamics.