Negative Thermal Expansion Near the Precipice of Structural Stability in Open Perovskites.

ABSTRACT: Negative thermal expansion (NTE) describes the anomalous propensity of materials to shrink when heated. Since its discovery, the NTE effect has been found in a wide variety of materials with an array of magnetic, electronic and structural properties. In some cases, the NTE originates from phase competition arising from the electronic or magnetic degrees of freedom but we here focus on a particular class of NTE which originates from intrinsic dynamical origins related to the lattice degrees of freedom, a property we term structural negative thermal expansion (SNTE). Here we review some select cases of NTE which strictly arise from anharmonic phonon dynamics, with a focus on open perovskite lattices. We find that NTE is often present close in proximity to competing structural phases,

SUBMITTER: Occhialini CA 

PROVIDER: S-EPMC6255880 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature