Thermophysical properties of multiple rare earth oxide co-doped zirconia-based ceramic materials

Rare earth (RE) oxides doping yttria stabilized zirconia (YSZ) is an effective path to improve the thermal-resistance and high-temperature stability of traditional ceramic YSZ thermal barrier coatings. Gd₂O₃-Yb₂O₃ co-doped YSZ (contain 3.5%Y₂O₃, mole fraction) (GY-YSZ) was prepared by sintering at 1500 ℃ for 24 h. The crystal structure and phase composition of the GY-YSZ were studied by XRD analysis. Laser flash method was used to investigate the effects of doping rare earth oxides on the thermophysical property of GY-YSZ. The results show that the thermal conductivity of the GY-YSZ doped with 2.0%~3.0% mole fraction of Gd₂O₃ and Yb₂O₃ is 0.90~1.15 W·(m·K)^-1, which is reduced by 30% at least than that of YSZ and proves the higher thermal-resistance property of the GY-YSZ. The influence mechanism of doping rare earth oxides on the thermal physical property of YSZ is that co-doping with Gd₂O₃ and Yb₂O₃ results in lattice distortion and content variation of monoclinic phase (M), tetragonal phase (T) and cubic phase (C) in YSZ.