金属镓在Bi(111)表面上的吸附和合金化  

Adsorption and Alloying of Gallium on Bi(111) Surface

作　　者：卢尧臣 张玉峰 白萌萌 李佐 曹龙江 陶敏龙[1] LU Yaochen;ZHANG Yufeng;BAI Mengmeng;LI Zuo;CAO Longjiang;TAO Minlong(School of Physical Science and Technology,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学物理科学与技术学院,重庆400715

出　　处：《西南师范大学学报（自然科学版）》2023年第1期56-62,共7页Journal of Southwest China Normal University(Natural Science Edition)

基　　金：国家自然科学基金(11804282);中央高校基本科研业务费专项(SWU-KQ22024)。

摘　　要：利用超高真空-低温隧道扫描显微镜,结合第一性原理计算,研究了金属镓原子在Bi(111)表面上的吸附和合金化过程.在低温条件下沉积镓原子,一部分镓原子会聚集在衬底表面形成小液滴,另一部分则会依附在Bi(111)台阶处形成略矮于原台阶高度的镓铋合金.在室温退火后,聚集的小液滴会脱附,被真空泵抽离后,样品表面的台阶边缘处留下大面积的镓铋合金,合金结构的晶向与衬底相同,原子排列方式为六角密排结构.模拟计算发现,沉积在Bi(111)表面的镓原子替代第2层的铋原子形成镓铋合金结构的能量最低,结构最稳定,且模拟的镓铋合金的层高与实验结果一致.The adsorption and alloying processes of gallium atoms on Bi(111) surface were studied by using ultra-high vacuum-low temperature scanning tunneling microscope combined with first-principles calculation. Gallium atoms were deposited at low temperature. Part of the gallium atoms were gathered on the substrate surface to form small droplets, and the other part were attach to Bi(111) step to form Ga-Bi alloy slightly lower than the height of the original step. After annealing at room temperature, the assembled droplets desorbed, leaving a large area of Ga-Bi alloy at the step edge of the sample surface. The crystal orientation of the alloy structure was the same as that of the substrate, and the atomic arrangement was the hexagonal close-packed structure. The simulation results showed that gallium atoms deposited on Bi(111) surface replace Bismuth atoms in the second layer to form a Ga-Bi alloy structure with the lowest energy and the most stable structure, and the layer height of the simulated Ga-Bi alloy was consistent with the experimental results.

关 键 词：镓 镓铋合金 第一性原理计算 Bi(111)表面 

分 类 号：O469[理学—凝聚态物理]