Vacancy defects effect on thermal conductivity of α-zirconium crystal

As a widely employed fuel cladding material in light water reactor, the thermal conductivity of zirconium alloy is an important property, especially under the condition of irradiation. In this work, the effects of vacancy on the electronic and phonon thermal conductivity of alpha-zirconium at 600 K is investigated. The electronic thermal conductivity is calculated by applying the first principles electronic structure to the semi-classical Boltzmann transport equation under the relaxation time approximation. The reverse non-equilibrium molecular dynamics simulation is used to calculate the phonon thermal conductivity. The thermal conductivity decreases with the increase of the vacancy concentration for both phonon and electronic cases. The electronic and phonon thermal conductivities of alpha-zirconium are at the same magnitude. The current work shows that the electron contribution to the total thermal conductivity is higher than that from phonon. Vacancies have a more serious effect on phonon thermal conductivity than the effect on electronic thermal conductivity. Our calculated thermal conductivity of a-zirconium agrees with experimental data well.