电子发射材料组成对Ba-W阴极性能的影响  

Effect of electron emission material composition on Ba-W cathode properties

作　　者：沈春英[1] 李志顺 丘泰[1] 

机构地区：[1]南京工业大学材料科学与工程学院,江苏南京210009 [2]南京三乐集团电子研究所,江苏南京211800

出　　处：《电子元件与材料》2010年第4期46-49,共4页Electronic Components And Materials

基　　金：国防基金资助项目

摘　　要：利用TGA-DSC和XRD对阴极铝酸盐添加氧化钪(Sc2O3)前后的合成工艺、产物物相等进行了研究,对合成后铝酸盐与钨基的浸渍工艺、阴极的发射性能及蒸发速率进行了分析。结果表明:铝酸盐主晶相为Ba5CaAl4O12,添加w(Sc2O3)3%后,主晶相改变为Ba3CaAl2O7,熔点下降了48.5℃,铝酸盐的浸渍温度降低了130℃,浸渍度略有升高,保温时间缩短了0.5min。在阴极工作温度(1000～1100℃)范围之内,添加Sc2O3后制备的铝酸盐阴极直流发射密度是普通铝酸盐阴极的2倍以上;1100℃时平均蒸发速率是普通铝酸盐的61.5%,性能明显优于普通铝酸盐。The synthesis process and phase composition of Sc2O3 doped aluminate, i.e. cathode B were investigated by thermal analysis （TGA-DSC） and X-ray diffraction （XRD）. At the same time, its impregnation process, emission properties and evaporation rate were analyzed as an electron emission material. The results show that with the addition 3% of w（Sc2O3）, the main crystal phase of the aluminate changes from Ba5CaAl4O12 into Ba3CaAl2O7, which is accompanied by a drop of 48.5 ℃ in melting point. Correspondingly, the holding temperature and time required for the impregnation process are decreased by 130 ℃and 0.5 minutes, respectively. In normal working temperature （1 000-1 100 ℃）, the direct current emission density of the cathode B is more than two times of ordinary aluminate cathode. At 1 100 ℃, the average evaporation rate of the cathode B is 61.5% of ordinary aluminate cathode. All the results indicate that the cathode B shows more superior properties than ordinary auminate cathode.

关 键 词：氧化钪 铝酸盐 钡钨阴极 电子发射材料 

分 类 号：TB742[一般工业技术—材料科学与工程]