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

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

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


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 neutrons cm-2. The quantitatively measured size distribution (average loop size = 3.6 ± 2.1 nm), number density of the dislocation loops (3.6 × 1022 m-3) and dislocation density (7.8 × 1013 m m-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
Pages (from-to)120-130
Number of pages11
Issue number2
Publication statusPublished - 2017 Apr 1


  • Diffraction contrast
  • Dislocation
  • Irradiation damage
  • STEM
  • Weak-beam

ASJC Scopus subject areas

  • Structural Biology
  • Instrumentation
  • Radiology Nuclear Medicine and imaging


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