A LAB6 Nanoneedle Field-Emission Electron Source for Stable Imaging with Atomic Resolution in a Transmission Electron Microscope

A LaB6 nanoneedle field-emission point electron source has been developed and installed in a spherical aberration- corrected transmission electron microscope (Cs-corrected TEM) for performance evaluations. A sub-Angstrom (0.96 Å) spatial resolution and small energy spread (0.38 eV) has been obtained. In addition, the LaB6 nanoneedle can work stably for more than 100 hours continuously with a fluctuation smaller than 1%, which showed more than ten times in improvement than the contemporary W(310) field- emitter and also showed the best stability in electron emission. This new electron source is expected to be applicable for other electron beam technologies, including cryo-EM, ultrafast-EM, electron beam lithography.