6533b834fe1ef96bd129dfb0
RESEARCH PRODUCT
Ab initio molecular dynamics simulations of the Sc K-edge EXAFS of scandium trifluoride
Alexei KuzminFrancesco RoccaAleksandr KalinkoMatthias KrackShehab E. AliDmitry BocharovDmitry BocharovJuris Puranssubject
Historychemistry.chemical_element02 engineering and technologyCrystal structureAtmospheric temperature rangeCubic crystal system021001 nanoscience & nanotechnologyScandium fluoride01 natural sciencesMolecular physicsComputer Science ApplicationsEducationX-ray absorption fine structureCrystallographychemistry.chemical_compoundchemistryNegative thermal expansionK-edge0103 physical sciencesScandium010306 general physics0210 nano-technologydescription
Scandium fluoride ScF3 has a simple cubic structure and attracts attention due to its large negative thermal expansion (NTE) over a wide range of temperatures (0-1100 K). In this study we present ab initio molecular dynamics (AIMD) simulations of ScF3 and their validation using the Sc K-edge EXAFS spectra in the temperature range from 300 K to 1000 K measured at the XAFS beamline of ELETTRA. The obtained results allow an assessement of the employed AIMD model and provide insight into the local structure and the lattice dynamics of ScF3 beyond the harmonic approximation. A strong anisotropy of the fluorine atom vibrations in the direction orthogonal to the -Sc-F-Sc- chain is observed. An expansion of the ScF6 octahedra is found upon increasing temperature despite of the overall NTE of the crystal.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-05-01 | Journal of Physics: Conference Series |