(Sm_(0.5)La_(0.5))_2Ce_2O_7的制备及热物理性能

Preparation and Thermophysical Properties of (Sm_(0.5)La_(0.5))_2Ce_2O_7

以La2O3、Sm2O3和CeO2为原料,基于固相反应法制备了(Sm0.5La0.5)2Ce2O7陶瓷,用X射线衍射(X-Ray Diffraction Method,简称XRD)分析了其物相组成,并采用扫描电子显微镜(SEM)和电子能谱(EDS)分析其显微组织和元素组成,最后,用激光脉冲法和推杆膨胀法分别测试了其热导率和热膨胀系数.结果表明,所制备的(Sm0.5La0.5)2Ce2O7陶瓷具有单一的萤石结构,其微观组织致密,晶界清晰,无其他相和未反应物存在;大半径La3+的引入不仅降低其热导率,而且提高了其热膨胀系数.

In this paper, the （Sm0.5La0.5 ）2Ce2O7 ceramic was synthesized by solid reaction using La203, Sm2O3 and CeO2 as raw materials. Its phase composition microstructure and composition was analyzed by X-ray diffraction, scanning electrical microscope （SEM） and electronic diffraction spectrum （EDS） , respectively. Its thermal diffusivity and thermal expansion coefficient are measured by laser flash method and pushing rod technique. Research results show that synthesized （ Sm0.5 La0.5 ）2 Ce2O7 ceramic has single fluorite structure and dense microstructure. No other phase or un-reacted oxides exist in the interfaces between grains. Its lower thermal conductivity and higher thermal expansion coefficient can be attributed to the La-doping.