Ab-initio modeling of Al.sub.2./sub.O.sub.3./sub. lattice instability under extreme excitation of the electronic system

0578980 - FZÚ 2024 RIV NL eng J - Journal Article
Voronkov, R. A. - Medvedev, Nikita - Rymzhanov, R.A. - Volkov, A.E.
Ab-initio modeling of Al₂O₃ lattice instability under extreme excitation of the electronic system.
Nuclear Instruments & Methods in Physics Research Section B. Roč. 435, Nov (2018), s. 87-92. ISSN 0168-583X. E-ISSN 1872-9584
R&D Projects: GA MŠMT LG15013
EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE
Institutional support: RVO:68378271
Keywords : nonthermal melting * electronic temperature * Al₂O₃ * laser spot * swift heavy ion track * density functional theory
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 1.210, year: 2018
Method of publishing: Limited access
https://doi.org/10.1016/j.nimb.2018.03.038

Nonthermal phase transformations induced in Al2O3 by the electronic temperatures above ∼2.5 eV is demonstrated with ab initio molecular dynamics simulations. When this temperature exceeds ∼4 eV, such a transformation occurs within ∼500 fs i.e. within the typical time-scale of relaxation of the excited electronic system in a micron-size spot of a femtosecond-laser pulse. The electronic temperature at least above 6–10 eV is required for a nonthermal melting to occur in Al2O3 within ∼50–100 fs, which is the time scale of cooling down of the electronic system in a swift heavy ion track. Because such level of the electronic temperature cannot be kept during all this time, we conclude that nonthermal melting of alumina in SHI tracks is implausible.
Permanent Link: https://hdl.handle.net/11104/0347867