Inoue Koji, Yoshida Kenta, Nagai Yasuyoshi, Kishida Kyosuke, Inui Haruyuki
Institute for Materials Research, Tohoku University, Oarai, Ibaraki, 311-1313, Japan.
Department of Materials Science and Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto, 606-8501, Japan.
Sci Rep. 2021 Feb 4;11(1):3073. doi: 10.1038/s41598-021-82705-3.
Atom probe tomography (APT) and transmission electron microscopy (TEM)/scanning transmission electron microscopy (STEM) have been used correlatively to explore atomic-scale local structure and chemistry of the exactly same area in the vicinity of growth front of a long-period stacking ordered (LPSO) phase in a ternary Mg-Al-Gd alloy. It is proved for the first time that enrichment of Gd atoms in four consecutive (0001) atomic layers precedes enrichment of Al atoms so that the formation of AlGd clusters occurs only after sufficient Al atoms to form AlGd clusters diffuse into the relevant portions. Lateral growth of the LPSO phase is found to occur by 'ledge' mechanism with the growth habit plane either {1[Formula: see text]00} or {11[Formula: see text]0} planes. The motion of ledges that give rise to lateral growth of the LPSO phase is considered to be controlled by diffusion of Al atoms.
原子探针断层扫描（APT）与透射电子显微镜（TEM）/扫描透射电子显微镜（STEM）已被关联使用，以探究三元Mg-Al-Gd合金中长周期堆垛有序（LPSO）相生长前沿附近完全相同区域的原子尺度局部结构和化学性质。首次证明，在四个连续的（0001）原子层中，Gd原子的富集先于Al原子的富集，因此只有在足够数量的Al原子扩散到相关部分以形成AlGd团簇之后，AlGd团簇才会形成。发现LPSO相的横向生长通过“台阶”机制发生，其生长习性面为{1[公式：见正文]00}或{11[公式：见正文]0}平面。导致LPSO相横向生长的台阶运动被认为是由Al原子的扩散控制的。
