Nonthermal phase transitions in metals

0533641 - FZÚ 2021 RIV GB eng J - Článek v odborném periodiku
Medvedev, Nikita - Milov, I.
Nonthermal phase transitions in metals.
Scientific Reports. Roč. 10, č. 1 (2020), s. 1-8, č. článku 12775. ISSN 2045-2322. E-ISSN 2045-2322
Grant CEP: GA MŠMT LTT17015
GRANT EU: European Commission(XE) 654148 - LASERLAB-EUROPE
Institucionální podpora: RVO:68378271
Klíčová slova: nonthermal phase transitions in metals under high electronic excitation * metal irradiation with ultrafast laser pulse
Obor OECD: Fluids and plasma physics (including surface physics)
Impakt faktor: 4.380, rok: 2020
Způsob publikování: Open access

It is well known that sufficiently thick metals irradiated with ultrafast laser pulses exhibit phonon hardening, in contrast to ultrafast nonthermal melting in covalently bonded materials. It is still an open question how finite size metals react to irradiation. We show theoretically that generally metals, under high electronic excitation, undergo nonthermal phase transitions if material expansion is allowed (e.g. in finite samples). The nonthermal phase transitions are induced via an increase of the electronic pressure which leads to metal expansion. This, in turn, destabilizes the lattice triggering a phase transition without a thermal electron-ion coupling mechanism involved. We find that hexagonal close-packed metals exhibit a diffusionless transition into a cubic phase, whereas metals with a cubic lattice melt. In contrast to covalent solids, nonthermal phase transitions in metals are not ultrafast, predicative on the lattice expansion.
Trvalý link: http://hdl.handle.net/11104/0311970