First-principles calculations of heat capacities of ultrafast laser-excited electrons in metals - Archive ouverte HAL Access content directly
Journal Articles Applied Surface Science Year : 2015

First-principles calculations of heat capacities of ultrafast laser-excited electrons in metals

(1) , (1) , (2) , (1)
1
2

Abstract

Ultrafast laser excitation can induce fast increases of the electronic subsystem temperature. The subsequent electronic evolutions in terms of band structure and energy distribution can determine the change of several thermodynamic properties, including one essential for energy deposition; the electronic heat capacity. Using density functional calculations performed at finite electronic temperatures, the electronic heat capacities dependent on electronic temperatures are obtained for a series of metals, including free electron like, transition and noble metals. The effect of exchange and correlation functionals and the presence of semicore electrons on electronic heat capacities are first evaluated and found to be negligible in most cases. Then, we tested the validity of the free electron approaches, varying the number of free electrons per atom. This shows that only simple metals can be correctly fitted with these approaches. For transition metals, the presence of localized d electrons produces a strong deviation toward high energies of the electronic heat capacities, implying that more energy is needed to thermally excite them, compared to free sp electrons. This is attributed to collective excitation effects strengthened by a change of the electronic screening at high temperature.
Fichier principal
Vignette du fichier
Ce-ass-v4.pdf (332.37 Ko) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

ujm-01134167 , version 1 (23-03-2015)

Identifiers

Cite

Emile Bévillon, Jean-Philippe Colombier, Vanina Recoules, Razvan Stoian. First-principles calculations of heat capacities of ultrafast laser-excited electrons in metals. Applied Surface Science, 2015, 336, pp.79-84. ⟨10.1016/j.apsusc.2014.09.146⟩. ⟨ujm-01134167⟩
47 View
415 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More