2026-05-28 早稲田大学
図１（左上）20面体原子クラスターおよび歪んだ20面体原子クラスターからなる中距離秩序構造。比較的短い柱状原子配列に対応する。（右上）実験で金属ガラスから得られた高分解能像。（左下）分子動力学シミュレーションで得られた金属ガラスモデルから計算した高分解能像。（右下）種々の原子クラスターからなる大きいサイズの柱状原子配列。左上や右下の柱状中距離秩序構造の中心軸に沿った原子の並びが、柱の軸方向から見た際の像中の輝点に対応する。右下の配列からは、左上のものと比べて、より輝度の高い輝点が期待される。
＜関連情報＞
- https://www.waseda.jp/inst/research/news/84551
- https://www.sciencedirect.com/science/article/pii/S1359645426004465
Zr-Pt金属ガラスにおける柱状原子配列とその高分解能電子顕微鏡像 Columnar atomic arrangements in Zr-Pt metallic glasses and their appearance in high-resolution electron microscopy
Siyuan Zha, Akihiko Hirata
Acta Materialia Available online 12 May 2026
DOI:https://doi.org/10.1016/j.actamat.2026.122344
Abstract
The characteristics of medium-range order structures in Zr80Pt20 metallic glasses were investigated through molecular dynamics simulations and transmission electron microscopy. Two dominant Pt-centered atomic clusters, icosahedral and icosahedral-like, were found to exhibit distinct spatial distribution characteristics in the simulated models. The icosahedral atomic clusters are connected through interpenetration, as commonly suggested, forming localized medium-range order. In contrast, the icosahedral-like atomic clusters tend to form more extended structures through edge- and face-sharing connections. The latter can be interpreted as interpenetrating when Zr-centered atomic clusters are taken into account. We also show that Zr-centered atomic clusters with relatively higher coordination numbers tend to form interpenetrating structures on a larger scale, compared with Pt-centered atomic clusters. Remarkably bright spots frequently observed in experimental high-resolution electron microscopy images were interpreted as columnar structures formed by atomic clusters aligned along the incident direction of the electron beam.
