Aberration-corrected STEM/TEM imaging at 15kV.

Authors :: Sasaki T
Sawada H
Hosokawa F
Sato Y
Suenaga K
Source :: Ultramicroscopy [Ultramicroscopy] 2014 Oct; Vol. 145, pp. 50-5. Date of Electronic Publication: 2014 Apr 29.
Publication Year :: 2014
Abstract: The performance of aberration-corrected (scanning) transmission electron microscopy (S/TEM) at an accelerating voltage of 15kV was evaluated in a low-voltage microscope equipped with a cold-field emission gun and a higher-order aberration corrector. Aberrations up to the fifth order were corrected by the aberration measurement and auto-correction system using the diffractogram tableau method in TEM and Ronchigram analysis in STEM. TEM observation of nanometer-sized particles demonstrated that aberrations up to an angle of 50mrad were compensated. A TEM image of Si[110] exhibited lattice fringes with a spacing of 0.192nm, and the power spectrum of the image showed spots corresponding to distances of 0.111nm. An annular dark-field STEM image of Si[110] showed lattice fringes of (111) and (22¯0) planes corresponding to lattice distances of 0.314nm and 0.192nm, respectively. At an accelerating voltage of 15kV, the developed low-voltage microscope achieved atomic-resolution imaging with a small chromatic aberration and a large uniform phase.<br /> (Copyright © 2014 Elsevier B.V. All rights reserved.)