Thermal conductivity of zirconia for thermal barrier coatings: A perturbed molecular dynamics study

Thermal conductivity of pure and Y₂O₃-doped ZrO ₂ was calculated using a perturbed molecular dynamics method in order to analyze phonon scattering mechanism which is responsible for the reduction of thermal conductivity. Although absolute values of thermal conductivity were overestimated due to a simple model used in this study, relative values were in good agreement with experiment, which indicates that phonon scattering due to Y₂O3 addition is reproduced well. It is found from quantitative analysis of the phonon scattering using the mean field theory that decrease of the thermal conductivity upon Y₂O₃ addition is attributed not only to the introduction of O_2- vacancies but also to substitution of Y³⁺ ions for Zr⁴⁺ ions.