作者：陈德平1, 唐海权2, 陈营1, 廖婷婷1, 周付宇1
作者单位：1. 成都工业学院材料与环境工程学院，四川 成都 610000;
2. 成都工具研究所有限公司，四川 成都 610000
关键词：密度泛函理论;表面结构;电子态密度
摘要：
采用基于密度泛函理论的CASTEP软件，首先优化Ni的晶格常数，研究金属Ni(111), Ni(100)和Ni(110)3个低指数表面的表面弛豫、表面能和表面电子态密度，研究结果表明：表面Ni的三个表面表面能最大的Ni(110)面，表面弛豫最大，表面能最小的Ni(111)面，表面弛豫最小；表面弛豫主要发生在前两层原子上，第一层向内收缩，第二层向外拉伸；弛豫后表面原子的态密度明显区别于体内原子，表面态密度变化越大，表面驰豫越大、表面能越大；表面悬键最多、配位最不饱和的Ni(110)晶面表面态密度大，表面能大，表面驰豫量多。发生在催化剂上的反应能量和反应速率相当敏感地依赖于裸露的表面晶面，因此裸露Ni(110)晶面的催化剂，相对于其低指数的基础晶面(111)、(100)，具有更好的活性，为催化剂的设计提供一定的理论依据。
First principles investigation of the surface of metal nickel
CHEN Deping1, TANG Haiquan2, CHEN Ying1, LIAO Tingting1, ZHOU Fuyu1
1. School of Materials and Environmental Engineering, Chengdu Technological University, Chengdu 610000, China;
2. Chengdu Tool Research Institute Co., Ltd., Chengdu 610000, China
Abstract: CASTEP software based on density functional theory was used to optimize the lattice constant of the Ni first, and the relaxation of the surface, surface energy, and surface electronic density of states of Ni(111), Ni(100)和Ni(110) three low index surface of metal Ni was studied, the results showed that the Surface relaxation of Ni(110) surface is maximum, and the surface energy is highest. the Surface relaxation of Ni(111) surface is minimum, and the surface energy is lowest; the surface relaxation mainly occured on the first two layers of atoms, with the first layer contracting inward and the second stretching outward. The state density of the relaxed surface atoms is obviously different from that of the atoms in the body, The more the DOS of surface changes, the more the surface relaxation and the bigger the surface energy;The Ni(110) crystal surface with the most suspended bonds on the surface and the least saturated coordination had the highest DOS of surface, the highest surface energy and the maximum surface relaxation. The reaction energy and reaction rate on the catalyst are quite sensitively dependent on the bare surface crystal surface. Therefore, the catalyst with bare Ni(110) crystal surface has better activity compared with other low index crystal surface(111), (100), which provides a certain theoretical basis for the design of the catalyst.
Keywords: density functional theory;surface structure;DOS
2021, 47(8):13-17 收稿日期: 2020-06-01;收到修改稿日期: 2020-08-21
基金项目: 四川省教育厅项目（18ZB0036）
作者简介: 陈德平(1986-),女,四川宜宾市人,讲师,硕士,研究方向为材料加工工程
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