He Zhanbing, Ma Haikun, Li Hua, Li Xingzhong, Ma Xiuliang
State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China.
Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588-0656, USA.
Sci Rep. 2016 Mar 1;6:22337. doi: 10.1038/srep22337.
A new kind of decagonal quasicrystal (DQC) with a periodicity of 1.23 nm was observed in the as-cast quaternary Al60Cr20Fe10Si10 alloy. The intensity distribution of some spots in the selected-area electron diffraction pattern along the tenfold zone axis was found to be different from other Al-based DQCs. High-angle annular dark-field scanning transmission electron microscopy was adopted to reveal the structural features at an atomic level. Both the tenfold symmetry and symmetry-broken decagonal (D) clusters of 1.91 nm in diameter were found, but with structural characteristics different from the corresponding D clusters in the other Al-based DQCs. The neighboring D clusters are connected by sharing one edge rather than covering, suggesting the tiling model is better than the covering model for structural description.
在铸态的四元Al60Cr20Fe10Si10合金中观察到一种具有1.23nm周期性的新型十边形准晶体（DQC）。发现沿十重晶带轴的选区电子衍射图中某些斑点的强度分布与其他铝基DQC不同。采用高角度环形暗场扫描透射电子显微镜在原子水平上揭示结构特征。发现了十重对称性和直径为1.91nm的对称破缺十边形（D）簇，但结构特征与其他铝基DQC中的相应D簇不同。相邻的D簇通过共享一条边而不是覆盖连接，这表明平铺模型比覆盖模型更适合用于结构描述。
