Al_(62)Cr_(17.5)Fe_(11)Si_(9.5)合金中的两类一维准晶  

Two types of one⁃dimensional quasicrystals in Al_(62)Cr_(17.5)Fe_(11)Si_(9.9)

作　　者：李花 何战兵[1] LI Hua;HE Zhan-bing(State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083;Department of Aerospace Science and Technology,Space Engineering University,Beijing 101407,China)

机构地区：[1]北京科技大学新金属材料国家重点实验室,北京100083 [2]航天工程大学宇航科学与技术系,北京101407

出　　处：《电子显微学报》2023年第4期401-409,共9页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金面上项目资助(No.52171151).

摘　　要：一维准晶是介于二维准晶和准晶近似相之间的一种具有一维准周期结构特点的准晶体,其在两个相互垂直的方向具有周期性,而在第三个方向具有准周期性。由于发现一维准晶的合金体系非常有限且基本限于准晶研究前期,因而我们对一维准晶体的晶体结构,尤其是其原子级的结构特点知之甚少。联合利用选区电子衍射及高角度环形暗场-扫描透射电子显微技术,作者在Al_(62)Cr_(17.5)Fe_(11)Si_(9.5)合金中发现了两种一维准晶,并首次在原子级别上研究了一维准晶的结构特点。研究表明,这两种一维准晶沿着相应的十次准晶一个二次轴方向(P方向)的周期分别约为2.98 nm和1.84 nm,其比值为黄金分割数τ。沿伪十次轴方向的高角度环形暗场-扫描透射电子显微像表明,一维准晶在该平面内的周期性主要来源于沿一个方向呈周期分布的直径为2 nm的十边形列。One⁃dimensional(1D)quasicrystals are the intermediate state between two⁃dimensional quasicrystals and their approximants.The structural characteristic of one⁃dimensional quasicrystal(1D)is very important for understanding the phase transition between the latter two.However,the structural feature of 1D quasicrystal is rarely studied at the atomic level.In this Letter,two 1D quasicrystals were observed in Al_(62)Cr_(17.5)Fe_(11)Si_(9.9)alloy by the combination of selected⁃area electron diffraction and high⁃angle annular dark field⁃scanning transmission electron microscopy.The period of the two 1D quasicrystals in one of twofold directions of the corresponding decagonal quasicrystal is about 2.98 nm and 1.84 nm,with a ratio of the golden section numberτ.The high⁃angle annular darkfield⁃scanning transmission electron micrographs along the pseudo⁃decagonal axis show that the periodicity of one⁃dimensional quasicrystals originates from the periodic distribution of the rows of 2 nm decagonal structure units along one direction in the pseudo tenfold plane.

关 键 词：Al⁃Cr⁃Fe⁃Si 一维准晶 准晶结构 HAADF⁃STEM 

分 类 号：TG146.2[一般工业技术—材料科学与工程] O753.3[金属学及工艺—金属材料] O766.1[金属学及工艺—金属学] TG115.215.3[理学—晶体学]