Entropic elasticity and negative thermal expansion in a simple cubic crystal
| Autor: | Katharine Page, Emil Bozin, David Wendt, Alexei V. Tkachenko, Joerg C. Neuefeind, Wei Ku, Brent Fultz, Igor Zaliznyak, Limin Wang |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Quantitative Biology::Tissues and Organs FOS: Physical sciences 02 engineering and technology Condensed Matter - Soft Condensed Matter Neutron scattering Cubic crystal system complex mixtures 01 natural sciences Condensed Matter::Materials Science Negative thermal expansion 0103 physical sciences 010306 general physics Condensed Matter - Statistical Mechanics Research Articles chemistry.chemical_classification Condensed Matter - Materials Science Quantitative Biology::Biomolecules Multidisciplinary Statistical Mechanics (cond-mat.stat-mech) Condensed matter physics technology industry and agriculture Materials Science (cond-mat.mtrl-sci) SciAdv r-articles Polymer Elasticity (physics) Physics::Classical Physics Condensed Matter Physics 021001 nanoscience & nanotechnology eye diseases Uncorrelated Universality (dynamical systems) body regions Condensed Matter::Soft Condensed Matter Quantitative theory chemistry Soft Condensed Matter (cond-mat.soft) sense organs 0210 nano-technology Research Article |
| Zdroj: | Science Advances |
| Popis: | While most solids expand when heated, some materials show the opposite behavior: negative thermal expansion (NTE). In polymers and biomolecules, NTE originates from the entropic elasticity of an ideal, freely-jointed chain. The origin of NTE in solids has been widely believed to be different. Our neutron scattering study of a simple cubic NTE material, ScF3, overturns this consensus. We observe that the correlation in the positions of the neighboring fluorine atoms rapidly fades on warming, indicating an uncorrelated thermal motion constrained by the rigid Sc-F bonds. This leads us to a quantitative theory of NTE in terms of entropic elasticity of a floppy network crystal, which is in remarkable agreement with experimental results. We thus reveal the formidable universality of the NTE phenomenon in soft and hard matter. 6 pages, 4 figures. Work reported at 2019 APS March meeting (http://meetings.aps.org/Meeting/MAR19/Session/B33.8) |
| Databáze: | OpenAIRE |
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