TEM based high resolution and low-dose scanning electron nanodiffraction technique for nanostructure imaging and analysis

We report a high resolution and low-dose scanning electron nanodiffraction (SEND) technique for nanostructure analysis. The SEND patterns are recorded in a transmission electron microscope (TEM) using a low-brightness ~2nm electron beam with a LaB₆ thermionic source obtained by a large demagnification of the condenser 1 lens. The diffraction pattern is directly recorded using a CCD camera optimized for low-dose imaging. A custom script was developed for calibration and automated data acquisition. The performance of low-dose SEND is evaluated using nanostructured Au as a test sample for the quality of diffraction patterns, sample stability and probe size. We demonstrate that our method provides an effective and robust way for recording diffraction patterns from nanometer-sized grains.