物理化学学报 >> 2011, Vol. 27 >> Issue (07): 1609-1614.doi: 10.3866/PKU.WHXB20110702

理论与计算化学 上一篇    下一篇

MgF2表面结构稳定性及电子特性的密度泛函理论研究

张莉莉1,2, 韩培德1,2, 张彩丽1,2, 董明慧1,2, 杨艳青1,2, 古向阳3   

  1. 1. 太原理工大学材料科学与工程学院, 太原 030024;
    2. 太原理工大学新材料界面科学与工程教育部重点实验室, 太原 030024;
    3. 太原理工大学机械工程学院, 太原 030024
  • 收稿日期:2011-01-11 修回日期:2011-04-03 发布日期:2011-06-28
  • 通讯作者: 韩培德 E-mail:hanpeide@tyut.edu.cn
  • 基金资助:

    国家自然科学基金(50874079)和太原市科技项目(100115105)资助

Density Functional Theory Study on the Stability and Electronic Properties of MgF2 Surfaces

ZHANG Li-Li1,2, HAN Pei-De1,2, ZHANG Cai-Li1,2, DONG Ming-Hui1,2, YANG Yan-Qing1,2, GU Xiang-Yang3   

  1. 1. College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China;
    2. Key Laboratory of Interface Science and Engineering in Advanced Materials of Taiyuai University of Technology, Ministry of Education, Taiyuan 030024, P. R. China;
    3. College of Mechanical Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China
  • Received:2011-01-11 Revised:2011-04-03 Published:2011-06-28
  • Contact: HAN Pei-De E-mail:hanpeide@tyut.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (50874079) and Taiyuan Science and Technology Project, China (100115105).

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摘要：

用密度泛函理论(DFT)研究了MgF2(010)、MgF2(001)、MgF2(011)及MgF2(110)四种表面10种构型的稳定性和电子特性. 结果表明: 四种表面的邻近表面几层原子均出现了明显的驰豫现象, 终止于单层F原子的表面相对稳定; 进一步对比分析四种表面(终止于单层F原子的稳定构型)的表面能发现, 稳定性依次减弱排列为MgF2(110)、MgF2(011)、MgF2(010)、MgF2(001); 最稳定的MgF2(110)表面的态密度显示在费米能级以下较多的成键电子处于低能级区, 同时由于表面的影响, 导致表面F原子电荷聚集显负电性, 促使表面活性增加.

关键词: 氟化镁, 密度泛函理论, 表面能, 稳定性, 态密度

Abstract:

The structural stability and electronic properties of MgF2(010), MgF2(001), MgF2(011), and MgF2(110) surfaces were investigated using density functional theory (DFT). We found that the atoms located in the top layers near the surface are obviously relaxed and that the fluorine-terminated surface structure is much more stable than the other two structures. According to the surface energy values of the four different fluorine-terminated surfaces we conclude that the structural stability of the MgF2 surfaces decreases in the following order: MgF2(110), MgF2(011), MgF2(010), and MgF2(001). The density of states of the MgF2(110) surface shows that more bonding electrons are in low level areas and, furthermore, because of the influence of the surface the fluorine atom charges gather at the surface, which makes the surface electronegative and results in an increase in its activity.

Key words: Magnesium fluoride, Density functional theory, Surface energy, Stability, Density of state