Molecular dynamics study on the thermal conductivity of BaZrO3: effect of out-of-plane thickness and oxygen vacancy concentration

BaZrO 3 is a new generation of perovskite-type thermal barrier coating material. In this paper, the non-equilibrium molecular dynamics (NEMD) method is adopted to systematically investigate how out-of-plane thickness and oxygen vacancy concentration affect the thermal conductivity of BaZrO 3 at 1000K. The results show that when the out-of-plane thickness increases from 5.05nm to 13.48 nm at 1000K, thermal conductivity increases from 1.313 Wm −1 K −1 to 1.723 Wm −1 K −1 , showing a significant size effect; When out-of-plane thickness is set at 5.05 nm, the oxygen vacancy concentration increases from 0 % to 0.31 %, thermal conductivity of the BaZrO 3 shows a continuous decline trend from 0.313 to 0.520 Wm −1 K −1 , which can be attributed to the defects and distortions caused by the low-dimensional transformation and oxygen vacancies. This study provides an important theoretical basis for the application of BaZrO 3 in the field of thermal barrier coating materials. • As out-of-plane thickness grows from 5nm to 20 nm at 1000K, thermal conductivity of BaZrO 3 film increases by 30%. • Oxygen-vacancy tuning (0–0.31at. %) induces up to a 60 % reduction in thermal conductivity via enhanced phonon scattering. • Effect of out-of-plane thickness and O v concentration on BaZrO 3 film thermal conductivity is systematically invetigated.