Weak-beam scanning transmission electron microscopy for quantitative dislocation density measurement in steels

Milan Konstantinovic, Kenta Yoshida, Masaki Shimodaira, Takeshi Toyama, Yasuo Shimizu, Koji Inoue, Toshimasa Yoshiie, Robert Gerard, Yasuyoshi Nagai

Research outputpeer-review


To evaluate dislocations induced by neutron irradiation, we developed a weak-beam scanning transmission electron microscopy (WB-STEM) system by installing a novel beam selector, an annular detector, a high-speed CCD camera and an imaging filter in the camera chamber of a spherical aberration-corrected transmission electron microscope. The capabilities of the WB-STEM with respect to wide-view imaging, real-time diffraction monitoring and multi-contrast imaging are demonstrated using typical reactor pressure vessel steel that had been used in an European nuclear reactor for 30 years as a surveillance test piece with a fluence of 1.09 × 1020 neutronscm–2. The quantitatively measured size distribution (average loop size = 3.6 ± 2.1 nm), number density of the dislocation loops (3.6 × 1022m−3) and dislocation density (7.8 × 1013mm–3) were carefully compared with the values obtained via conventional weak-beam transmission electron microscopy studies. In addition, cluster analysis using atom probe tomography (APT) further demonstrated the potential of the WB-STEM for correlative electron tomography/ APT experiments
Original languageEnglish
Article number66
Pages (from-to)120-130
Number of pages10
JournalJournal of Microscopy
Issue number2
StatePublished - 18 Jan 2017

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