(La_(0.95)Mg_(0.05))_2Ce_2O_(6.95)陶瓷的制备及热导率

Preparation and Thermal Conductivity of (La_(0.95)Mg_(0.05))_2Ce_2O_(6.95) Ceramics

以La2O3、MgO和CeO2为原料,采用固相反应法制备了(La0.95Mg0.05)2Ce2O6.95陶瓷。用X射线衍射(XRD分析了其相结构,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,用激光脉冲法测试了热导率。结果表明,所制备的(La0.95Mg0.05)2Ce2O6.95具有单一的萤石结构,其微观组织致密,晶界清晰,无其他相和微反应物存在。氧空位及取代原子的共同作用,使其具有比La2Ce2O7更低的热导率,该材料有潜力用作新型热障涂层表面陶瓷层材料。

The （La0.95Mg0.05）2Ce2O6.95 ceramic was synthesized by solid reaction method using La203, MgO and CeOz as raw materials. Its phase-structure was analyzed by X-ray diffraction （XRD）, the microstructure and elemental composition were examined by scanning electrical microscope （SEM） and electronic diffraction spectrum （EDS）, and its thernlal conductivity was investigated by laser-flash method. Results show that the synthesized （La0.95Mg0.05）2Ce2O6.95 ceramic has single fluorite structure, its microstructure is very dense. No other phase or un-reacted oxides exist in the enter faces between grains. The phonon scattering resulted by oxygen vacancy and substitution atoms led to its lower therma conductivity as compared to that of La2Ce2O7. The synthesized （La0.95Mg0.05）2Ce2O6.95 can be used as candidate material for ceramic-layer in new thermal barrier coatings.