Evaluation of Aberration-corrected Optical Sectioning for Exploring the Core Structure of 1/2[111] Screw Dislocations in BCC Metals

0483111 - ÚFM 2019 RIV US eng J - Journal Article
Hernandez-Maldonado, D. - Gröger, Roman - Ramasse, Q. M. - Hirsch, P. B. - Nellist, P. D.
Evaluation of Aberration-corrected Optical Sectioning for Exploring the Core Structure of 1/2[111] Screw Dislocations in BCC Metals.
Microscopy and Microanalysis. Roč. 23, č. 1 (2017), s. 432-433. ISSN 1431-9276. E-ISSN 1435-8115
R&D Projects: GA ČR(CZ) GA16-13797S; GA MŠMT(CZ) LQ1601
Institutional support: RVO:68081723
Keywords : optical sectioning * screw dislocation * electron microscopy
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 2.124, year: 2017

The introduction of spherical-aberration correctors in the Scanning Transmission Electron Microscope
(STEM) has allowed an improvement in spatial resolution to the sub-angström scale accompanied by a
reduction of the depth of focus (due to the increase in probe convergence angles), which in a modern
instrument is just a few nanometers, thus often less than the sample thickness. This can be exploited to
extract information along the beam direction by focusing the electron probe at specific depths within the
sample. In this communication we will evaluate the optical sectioning technique to explore the core structure of
1/2[111] screw dislocations in body-centred cubic (BCC) metals. The study of this structure is of high
interest because the low-temperature plastic deformation of BCC metals is controlled by the glide of
1/2[111] screw dislocations. The aim of this work is to investigate whether the edge and screw displacements
associated with 1/2[111] screw dislocations in BCC metals can be detected by optical sectioning in high-angle
annular dark field (HAADF) imaging in STEM conditions.
Permanent Link: http://hdl.handle.net/11104/0278542