一种新型激光镀锆/钪钡铝酸盐复合薄膜的钪型阴极的研究

Study on New Scandate Cathode Coated with Zr/Scandium Barium Aluminate by Pulsed Laser Deposition

钪型阴极具有优异的电子发射潜力,但同时也存在着发射均匀性和重复性差等共性问题。本研究提出采用脉冲激光镀膜技术在浸渍钪型阴极表面沉积锆/高活性钪钡铝酸盐复合叠层薄膜,以实现对其性能的改进。实验完成了阴极表面膜层的制备,阴极二极管电子发射性能测试,阴极表面光/热发射电子显微镜观察,以及激活阴极表面成分及其深度方向分布的俄歇电子显微镜分析。结果表明,覆膜钪型阴极激活后,其表面Ba、Sc含量提升,获得了110~130 nm厚的活性层,阴极展现出良好的发射性能,在1100℃脉冲条件下测得最大发射电流密度达到552A/cm^(2);同时,阴极的表面发射均匀性获得明显提升。

Scandate cathodes have excellent electron emission properties,but they also have some problems such as emission non-uniformity and poor repeatability.To improve the performance of the cathodes,a method of depositing composite film on the surface of scandate cathode by pulsed laser deposition technology was proposed.The film was deposited using zirconium and high-active barium aluminate salt target alternately.In the study,the coated scandate cathode was prepared,and its electron emission performance was tested.Microscopic observation of photo/thermal emission electron on the cathode surface was carried out,and Auger electron spectroscopy analysis of the surface composition and its depth distribution of the cathode was also processed.The results show that more Ba and Sc content are detected on the coated cathode surface after activation.An active layer with thickness of 110~130 nm is obtained.The cathode exhibits great emission performance,and the maximum emission current density measured under the pulse condition of 1100℃reaches 552 A/cm^(2).At the same time,the electron emission uniformity of the cathode has been significantly improved.