(北京工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院， 北京 100022)
摘 要: 采用“液液摻雜—冷凍干燥—兩段還原—SPS”法制備了納米W-La2O3發(fā)射材料， 利用原位俄射電子能譜分析技術(shù)研究了高溫過程中發(fā)射材料的表層元素含量以及縱向元素分布，并采用自行研制的微機(jī)控制全自動電子發(fā)射測量裝置測試了材料發(fā)射性能。 研究表明： 納米W-La2O3發(fā)射材料的有效逸出功為2.92 eV， 1 773 K下零場發(fā)射電流密度為2.52 A/cm2； 加熱過程中， 材料體內(nèi)以La2O3形式存在的鑭、氧向表面擴(kuò)散， 在表層10 nm的地方出現(xiàn)La、 O富集區(qū)， 并形成了超額La， 對電子發(fā)射起積極作用。
關(guān)鍵字: W-La2O3材料; 熱電子發(fā)射; 逸出功
nano-composite W-La2O3 material
ZHAI Li-li, ZUO Tie-yong
（ College of Materials Science and Engineering,
Beijing University of Technology, Beijing 100022, China）
Abstract: Nanocomposite W-La2O3 material was prepared by freeze-drying and its thermonic electron emission ability was measured. Surface behavior and depth profile of material from 298 to 1 573 K were in-situ investigated by Auger electron spectrometry. The results show that the nanocomposite W-La2O3 material shows good electron emission performance with the saturated current density of 2.52 A/cm2 at 1 773 K and work function of about 2.92 eV. During heating La and O atoms in La2O3 diffuse to the surface to form a La and O rich layer at ion depth, which makes the material have good emission ability.
Key words: W-La2O3 material; thermionic emission; work function
