Tang Shuai, Tang Jie, Wu Yimeng, Chen You-Hu, Uzuhashi Jun, Ohkubo Tadakatsu, Qin Lu-Chang
National Institute for Materials Science, Tsukuba, Ibaraki 305-0047, Japan.
Graduate School of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8857, Japan.
Nanoscale. 2021 Oct 21;13(40):17156-17161. doi: 10.1039/d1nr04907k.
A single CeB nanoneedle structure has been fabricated using a focused ion beam (FIB) and its field emission characteristics have been evaluated. A converged electron beam has been obtained, attributed to its sharpened tip with a radius of curvature of about 10 nm. Combined with its low work function, the required electric field is as low as 1.6 V nm to generate a field emission current of 50 nA. The most outstanding feature of the CeB nanoneedle emitter is its excellent current stability that enabled continuous emission for 16 hours with a fluctuation of 1.6% and without deterioration even in a vacuum of 10 Pa. The stable field-emission is attributed to the nanometric tip radius that led to reduction in gas adsorption and desorption. In addition, the downward dipolar structure on the emission surface is also beneficial for making the surface inert. These performance factors make CeB a practical field-emission point electron source for microscopy applications.
利用聚焦离子束（FIB）制备了单个CeB纳米针结构，并对其场发射特性进行了评估。由于其尖端锐化，曲率半径约为10 nm，因此获得了会聚电子束。结合其低功函数，产生50 nA场发射电流所需的电场低至1.6 V/nm。CeB纳米针发射器最突出的特点是其出色的电流稳定性，即使在10 Pa的真空中，也能连续发射16小时，波动为1.6%，且不会劣化。稳定的场发射归因于纳米级的尖端半径，这导致气体吸附和解吸减少。此外，发射表面上的向下偶极结构也有利于使表面呈惰性。这些性能因素使CeB成为显微镜应用中实用的场发射点电子源。
