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MM: Fachverband Metall- und Materialphysik
MM 5: Liquid and Amorphous Metals - Kinetics and Modelling
MM 5.5: Vortrag
Montag, 16. März 2020, 11:15–11:30, IFW D
Ultrafast melting of antimony after fs laser excitation: experiment meets fully ab-initio simulations — •Bernd Bauerhenne1, Sascha Epp2, Felipe Valencia3, and Dwayne R. J. Miller2 — 1Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany — 2Max-Planck-Institut für Struktur und Dynamik der Materie, Luruper Chaussee 149, Geb. 99, 22761 Hamburg, Germany — 3National University of Colombia, Cra 45, Bogota, Columbia
The time-resolved Bragg peak decay of a fs-laser pulse excited 30 nm thick antimony film was measured using x-ray pulses generated from a free electron laser. To predict this measured Bragg peak decay, we derived an electronic temperature (Te) dependent interatomic potential for antimony. For this, we fitted forces and energies obtained from ab-initio MD simulations of a thin antimony film at increased Te. Furthermore, we calculated the optical properities and the Te-depend electron-phonon coupling constant for antimony ab-initio. Utilizing the Te-dependent interatomic potential, the derived optical properites and the electron-phonon coupling constant, we performed MD simulations of a laser-excited 30 nm thick antimony film containing 9072 atoms. The calculated time-dependence of the Bragg-peaks shows very dood agreement with the experiment. Antimony melts within 600 fs for the highest considered laser intensity.