A molecular dynamics study of the thermal conductivity of uranium mononitride

Abstract

The thermal conductivity of uranium mononitride (UN) in the temperature range of 300–2000 K was estimated by molecular dynamics (MD) calculation on the basis of Green-Kubo relation. The Morse-type added to the Busing-Ida type function was adopted as the interatomic potential function. The parameters of the interatomic potential were determined by fitting the changes in the lattice parameters with temperature and pressure to experimental values in the literature. The temperature dependence of the calculated thermal conductivity followed a 1/ T law, suggesting that the lattice contribution to the thermal conductivity ( λ lat) was evaluated by the molecular dynamics calculation. The electronic contribution to the thermal conductivity ( λ el) was conjectured by Wiedemann-Franz law using the electrical resistivity data in the literature, and the temperature dependence of λ lat+ λ el was compared with the reported experimental data. The values of λ lat+ λ el obtained in the present study agreed with the literature values of the thermal conductivity. In the present study it was found that the MD simulation technique was useful and applicable to estimate the lattice thermal conductivity of UN.