Low-voltage coherent electron imaging based on a single-atom electron
Abstract
It has been a general trend to develop low-voltage electron microscopes due to their high imaging contrast of the sample and low radiation damage. Atom-resolved transmission electron microscopes with voltages as low as 15-40 kV have been demonstrated. However, achieving atomic resolution at voltages lower than 10 kV is extremely difficult. An alternative approach is coherent imaging or phase retrieval imaging, which requires a sufficiently coherent source and an adequately small detection area on the sample as well as the detection of high-angle diffracted patterns with a sufficient resolution. In this work, we propose several transmission-type schemes to achieve coherent imaging of thin materials (less than 5 nm thick) with atomic resolution at voltages lower than 10 kV. Experimental schemes of both lens-less and lens-containing designs are presented and the advantages and challenges of these schemes are discussed. Preliminary results based on a highly coherent single-atom electron source are presented. The image plate is designed to be retractable to record the transmission patterns at different positions along the beam propagation direction. In addition, reflection-type coherent electron imaging schemes are also proposed as novel methods for characterizing surface atomic and electronic structures of materials.
Cite
@article{arxiv.1512.08371,
title = {Low-voltage coherent electron imaging based on a single-atom electron},
author = {Wei-Tse Chang and Chun-Yueh Lin and Wei-Hao Hsu and Mu-Tung Chang and Yi-Sheng Chen and En-Te Hwu and Ing-Shouh Hwang},
journal= {arXiv preprint arXiv:1512.08371},
year = {2015}
}