| Autor: |
Handunkanda SU; Department of Physics, University of Connecticut, Storrs, CT 06269, United States of America. Institute for Materials Science, University of Connecticut, Storrs, CT 06269, United States of America., Curry EB, Voronov V, Hancock JN |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of physics. Condensed matter : an Institute of Physics journal [J Phys Condens Matter] 2020 Jan 16; Vol. 32 (3), pp. 035403. Date of Electronic Publication: 2019 Sep 30. |
| DOI: |
10.1088/1361-648X/ab4955 |
| Abstrakt: |
Simple cubic 'open' perovskite ScF 3 stands out among trifluoride materials in its large, isotropic negative thermal expansion (NTE), but also its proximity of its zero-temperature state to a structural phase transition. Here we report a temperature- and frequency-dependent lattice dynamical study of Brillouin zone center lattice excitations of single crystals of ScF 3 using infrared reflectivity measurements. In addition to quantifying the mode strengths and energies in single crystals of this interesting material, we also find strong evidence for multiphonon absorption processes which excite the zone-edge incipient soft modes associated with NTE and the structural quantum phase transition. In this way, we identify an optically-allowed pathway to excite soft modes provides a means to athermally populate modes associated with NTE in ScF 3 . |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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