液相共沉淀法制备612钪酸盐前驱体的研究

Study on Preparation of 612 Scandate Precursor

研究了以Ba（NO3）2、Ca（NO3）2、Al2（CO3）3为原料,添加3%Sc（NO3）3,采用液相共沉淀法制备扩散型阴极用612钪酸盐前驱体。以TG-DSC曲线和XRD、SEM分析了钪酸盐前驱体的焙烧工艺？焙烧产物的物相结构和颗粒形貌。结果表明：与机械混合法相比,液相共沉淀法制备的612钪酸盐前驱体颗粒更细,呈准球形,平均粒径0.2~0.5μm,Sc分布更均匀;合成温度为1 150℃,保温3 h;主要物相组成为质量分数在95%以上、具有发射活性的Ba3CaAl2O7。

The 612 scandate precursor using in dispenser cathode was prepeared by chemical liquid phase co-precipitations using Ba（NO3）2、Ca（NO3）2、Al2（CO3）3 as raw materials and adding 3% Sc2O3.The roasting process,phase composition and morphological characteristics were analyzed by TG,DSC,XRD and SEM.The results showed that the chemical liquid phase co-precipitations method was better than mechanical mixing method,prepared 612 scandate precursor powder was torispherical,the average particle size is of 0.2-0.5 μm,Sc distributes uniformly,the synthesis temperature 1 150 ℃ for 3 h,the main phase composition Ba3CaAl2O7 with electron emission was above 95%.