Transport and optical properties of warm dense aluminum in the two-temperature regime: Ab initio calculation and semiempirical approximation

Abstract

This work is devoted to the investigation of transport and optical properties of liquid aluminum in the two-temperature case. At first optical properties, static electrical and thermal conductivities were obtained in the ab initio calculation. The ab initio calculation is based on the quantum molecular dynamics, density functional theory and the Kubo-Greenwood formula. The semiempirical approximation was constructed based on the results of the ab initio caculation. The approximation yields the dependences σ 1DC ∝ 1/T 0.25 i and K ∝ T e /T 0.25 i for the static electrical conductivity and thermal conductivity, respectively. The approximation is valid for liquid aluminum at ρ = 2.70 g/cm 3 , 3 kK ≤ T i ≤ T e ≤ 20 kK. Our results are well described by the Drude model with the effective relaxation time τ ∝ T −0.25 i . We have compared our results with a number of other models. They are all reduced in the low-temperature limit to the Drude model with different expressions for the relaxation time τ . Our results are not consistent with the models in which τ ∝ T −1 i and support the models which use the expressions with the slower decrease of the relaxation time.

The Thermophysical Properties of Iron Plasma

“…Thus, the average charge of the cell (or the average ion charge Z ion ) is possible to introduce. The Kubo-Greenwood relations can be used within AAM to obtain the transport coefficients [16] as well as in ab initio approaches [14]. But the ion-ion correlations in AAM can be included only by means of the boundary conditions for the electron wave function.…”

“…Each approach supposes some model of a substance (plasma) itself. The most rigorous and advanced approaches, possibly, are so-called ab initio methods [11,13,14]. They treat a substance as two-component medium, consisting of classical nuclei and degenerate electrons.…”

“…That is why they fit very well for the calculations at relatively high densities (in liquids). But at the relatively small densities some general problems can hinder the application of these approaches (see [13][14][15][16][17][18][19]). In particular, there is no unique way to define the parameters necessary for their implementation (i.e.…”

Thermodynamic, transport, and optical properties of dense silver plasma calculated using the GreeKuP code

“…[31]). [23,24,32] However, our papers [23,24,32] give the correct L mn values, corresponding to the definitions (4) and (5). The incorrect definition of the Onsager coefficients (without e ) is present in a number of works, [17] including our earlier ones.…”

“…[24,25] As a result of the first stage, we obtain the ionic trajectories, temporal dependences of the total energy of electrons and ions E(t), and the total pressure of electrons and ions p(t). [24,25] As a result of the first stage, we obtain the ionic trajectories, temporal dependences of the total energy of electrons and ions E(t), and the total pressure of electrons and ions p(t).…”