Anomalous thermal expansion, negative linear compressibility, and high-pressure phase transition in ZnAu2(CN)4: Neutron inelastic scattering and lattice dynamics studies
File(s)
Published version
OA Location
Author(s)
Type
Journal Article
Abstract
We present temperature-dependent inelastic-neutron-scattering measurements, accompanied by ab initio calculations of the phonon spectra and elastic properties as a function of pressure to quantitatively explain an unusual combination of negative thermal expansion and negative linear compressibility behavior of ZnAu2(CN)4. The mechanism of the negative thermal expansion is identified in terms of specific anharmonic phonon modes that involve bending of the -Zn-NC-Au-CN-Zn- linkage. The soft phonon at the L point at the Brillouin zone boundary quantitatively relates to the high-pressure phase transition at about 2 GPa. The ambient pressure structure is also found to be close to an elastic instability that leads to a weakly first-order transition.
Date Issued
2017-12-01
Date Acceptance
2017-12-01
Citation
Physical Review B: Condensed Matter and Materials Physics, 2017, 96 (21)
ISSN
1098-0121
Publisher
American Physical Society
Journal / Book Title
Physical Review B: Condensed Matter and Materials Physics
Volume
96
Issue
21
Copyright Statement
© 2017 American Physical Society.
Subjects
02 Physical Sciences
03 Chemical Sciences
09 Engineering
Fluids & Plasmas
Publication Status
Published
Date Publish Online
2017-12-22