Enhancement of thermal properties of ytterbium-cerium oxide by zirconium doping for thermal barrier coatings

摘要

Rare-earth cerium oxides (RE2Ce2O7, RE?=?rare-earth elements) are proposed as promising thermal barrier coatings (TBCs) material due to large thermal expansion coefficient (TEC), phase stability and a comparable thermal cycling life to Yttria-Stabilized Zirconia (YSZ). However, the thermal conductivity of RE2Ce2O7 is relatively higher than that of both YSZ and rare-earth zirconates. Here, we report an effective method of reducing the thermal conductivity of Yb2Ce2O7 by Zr-doping. It is shown that, due to the strong phonon scattering caused by mass and radius differences between Ce4+ and Zr4+ ions, and disorder introduced into structures, the thermal conductivity of solid solutions is remarkably reduced with the increasing of Zr4+ content. Considering the high TEC, the Zr-doped Yb2Ce2O7 solid solutions are believed to be promising candidate materials for TBCs at elevated temperature.