Study of the two-temperature heat transfer model in metal nanofilms exposed to ultrashort laser pulses

• Main Authors: Kudinov, Igor V., Sobolev, Sergey L., Mikheeva, Galina V.
• Format: Conference Proceeding
• Language: English
• Subjects: Crystal lattices; Electron gas; Electrons; Equalization; Finite difference method; Gas temperature; Heat exchange; Heat transfer; Heat transfer coefficients; Lasers; Mathematical models; Metal films; Temperature; Temperature distribution
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0025795

The two-temperature mathematical model of an electron gas and a crystal lattice was used to study the heat exchange process in metal nanofilms exposed to ultrashort laser pulses. Numerical calculations for this model were performed using the finite difference method. It has been demonstrated that, all other conditions being equal, the volumetric heat transfer coefficient has the largest effect on the temperature field in the nanofilm. In particular, when this coefficient is small, the electron gas temperature significantly differs from that of the crystal lattice. As increases, the temperature of electrons in the jump caused by the laser source decreases due to a more intensive heat transfer from the electron gas to the lattice. It has been demonstrated that the temperature of the electron gas can be lower than that of the crystal lattice. This is due to differing rates of spatial temperature equalization (the heat capacity of the electron gas is much lower than that of the crystal lattice). In thinner metal films, the electron gas and crystal lattice temperatures change without a spatial gradient.