摘要
用密度泛函理论(DFT)研究了MgF_2(010)、MgF_2(001)、MgF_2(011)及MgF_2(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MgF_2(110)、MgF_2(011)、MgF_2(010)、MgF_2(001);最稳定的MgF_2(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.
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.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2011年第7期1609-1614,共6页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(50874079)
太原市科技项目(100115105)资助~~
关键词
氟化镁:密度泛函理论:表面能:稳定性:态密度
Magnesium fluoride
Density functional theory
Surface energy
Stability
Density of state
