Density functional theory study on the stability and electronic properties of MgF2 surfaces

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. © Editorial office of Acta Physico-Chimica Sinica.