Dy_2Ce_2O_7和Y_2Ce_2O_7稀土铈酸盐的制备及热导率

PREPARATION AND THERMAL CONDUCTIVITIES OF Dy_2Ce_2O_7 and Y_2Ce_2O_7 RARE EARTH CERIUM OXIDES

采用固相反应法在1600℃下保温10小时制备了Dy2Ce2O7和Y2Ce2O7陶瓷材料。分析了其相组成、微观组织和热导率。XRD结果表明,成功合成了具有萤石晶体结构的单一相Dy2Ce2O7和Y2Ce2O7。其组织结构致密,晶界清晰,无未反应物或杂质相存在。由于氧空位以及取代原子与基质原子之间的质量差异所导致的声子散射,使得Dy2Ce2O7和Y2Ce2O7具有比YSZ更低的热导率,这些结果表明,Dy2Ce2O7和Y2Ce2O7均可用作将来热障涂层用候选材料。

Dy 2Ce2O7 ceramic materia l was prepared by solid reaction at 1600℃ for 10h.The phase composition,microstructure and thermal conductivity of this material were investigated.XRD results reveals that single phase Dy 2Ce2O7 with fluorite structure was synthesized.Microstructure of Dy2Ce2O7 was dense and no other unreacted oxides or interphase existed in the interfaces between grains.Because of phonon scattering by oxygen vacancies and difference in atomic mass between substitutional atoms and host atoms,thermal conductivity of Dy 2Ce2O7 is lower than that of 8YSZ,which implies that this ceramic can be used as novel candidate materials for thermal barrier coatings in the future.