Kyushu University / Hata Laboratory

Atomic-resolution STEM / Short-range order

Atomic-scale STEM analysis of short-range order and nanoclusters

Atomic arrangements in alloys are neither completely random nor perfectly ordered. Short-range ordered structures and nanoclusters are subtle local variations in atomic arrangement that are often difficult to detect in conventional phase diagrams, yet they strongly influence dislocation motion, work hardening, the early stages of precipitation, and ultimately the mechanical properties of materials. In our laboratory, we visualize previously inaccessible fluctuations in atomic arrangements through the combined use of atomic-resolution STEM, electron diffraction, spectroscopy, and computational science, and clarify their relationships with material properties.

Key Points

Capturing Subtle Atomic Arrangements

By combining atomic-number contrast imaging, diffraction information, and elemental mapping, we analyze subtle local atomic arrangements that emerge prior to the formation of long-range ordered phases.

Understanding Interactions with Dislocations

We investigate how nanoclusters and short-range ordered structures influence dislocation slip behavior, local strain fields, and the heterogeneity of plastic deformation.

Expansion into International Collaborations

We conduct collaborative research with domestic and international research groups on a variety of materials, including aluminum alloys, TiAl-based alloys, high-entropy alloys, and steels.

Related Publications and Information

Selected publications and related information on this topic are listed below.