Melting and thermal ablation of a silver film induced by femtosecond laser heating: a multiscale modeling approach

• Published in: Applied physics. A, Materials science & processing Vol. 123; no. 10; pp. 1 - 14
• Main Authors: Ji, Pengfei, Zhang, Yuwen
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2017; Springer Nature B.V
• Subjects: Ablation; Applied physics; Characterization and Evaluation of Materials; Computer simulation; Condensed Matter Physics; Conduction heating; Conductive heat transfer; Coupling (molecular); Excitation; Femtosecond pulses; Heat transfer; Laser beam heating; Lasers; Machines; Manufacturing; Materials science; Molecular dynamics; Nanotechnology; Nuclear electric power generation; Optical and Electronic Materials; Phase transitions; Physics; Physics and Astronomy; Processes; Pulse heating; Quantum mechanics; Specific heat; Surfaces and Interfaces; Thermal conductivity; Thermal energy; Thermophysical models; Thin Films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-017-1269-7

The femtosecond laser pulse heating of silver film is investigated by performing quantum mechanics (QM), molecular dynamics (MD), and two-temperature model (TTM) integrated multiscale simulation. The laser excitation dependent electron thermophysical parameters (electron heat capacity, electron thermal conductivity, and effective electron–phonon coupling factor) are determined from ab initio QM calculation, and implemented into TTM description of electron thermal excitation, heat conduction, as well as electron–phonon coupled thermal energy transport. The kinetics of atomic motion is modeled by MD simulation. Energy evolution of excited electron subsystem is described by TTM in continuum. The MD and TTM are coupled by utilizing the effective electron–phonon coupling factor. Laser heating with varying laser fluences is systematically studied to determine the thresholds of homogeneous melting and ablation. The thermal ablation induced by rapid expansion of locally and excessively superheated silver is reported. This paper provides a basis for interpreting the phase-change process induced by laser heating, and facilitates the advancement of femtosecond laser pulse processing of material.