Journal article
Large angle illumination enabling accurate structure reconstruction from thick samples in scanning transmission electron microscopy
HG Brown, R Ishikawa, G S´anchez-Santolino, N Shibata, Y Ikuhara, LJ Allen, SD Findlay
Ultramicroscopy | ELSEVIER | Published : 2019
Abstract
Most reconstructions of the electrostatic potential of a specimen at atomic resolution assume a thin and weakly scattering sample, restricting accurate quantification to specimens only tens of Ångströms thick. We demonstrate that using large-angle-illumination scanning transmission electron microscopy (STEM)—a probe forming aperture with convergence angle larger than about 50 mrad—allows us to better meet the weak phase object approximation and thereby accurately reconstruct the electrostatic potential in samples thicker than the order of 100 Å.
Grants
Awarded by Ministry of Education, Culture, Sports, Science and Technology
Funding Acknowledgements
This research was supported under the Australian Research Councils Discovery Projects funding scheme (projects no. DP140102538 and DP160102338). A part of this work is supported by KAKENHI JSPS grant no. 17H01316, 17K18974, JST SENTAN, JST PRESTO and Grant-in-Aid for Specially Promoted Research atom-by-atom imaging of ion dynamics in nano-structures for materials innovation (grant no. JP17H06094). A part of this work was conducted in Research Hub for Advanced Nano Characterization, the University of Tokyo, under the support of Nanotechnology Platform (project no. 12024046) by MEXT, Japan.