Possible electronic entropy-driven mechanism for non-thermal ablation of metals

Abstract

The physical mechanism for metal ablation induced by femtosecond laser irradiation was investigated. Results of calculations based on finite-temperature density functional theory (FTDFT) indicate that condensed copper becomes unstable at high electron temperatures due to an increase of electronic entropy at large volume, where the local density of states near the Fermi energy increases. Based on these results, an electronic entropy-driven (EED) model is proposed to explain metal ablation with a femtosecond laser. In addition, a mathematical model is developed for simulation of the laser ablation, where the effect of the electronic entropy is included. This mathematical model can quantitatively describe the experimental data in the low-laser-fuence region, where the electronic entropy effect is determined to be especially important.

arXiv comment5 pages, 4 figures

References in corpus (3)

• Ab initio phonon coupling and optical response of hot electrons in plasmonic metals
• Entropy driven atomic motion in laser-excited bismuth
• First-principles calculations of heat capacities of ultrafast laser-excited electrons in metals

Cited by in corpus (3)

• Development of the temperature-dependent interatomic potential for molecular dynamics simulation of metal irradiated with an ultrashort pulse laser
• Microscopic mechanism of ultrashort-pulse laser ablation of metals: a molecular dynamics study incorporating electronic entropy effects
• {\it Ab initio} approach to the lattice softening of an Al slab driven by collective electronic excitations after ultrashort laser pulse irradiation