Density Functional Theory Investigation On The Superficial And Interfacial Structure Of NiO

NiO is an important antiferrferromagnet, which is applied in catalysis, magnetic devices and high temperature superconduct. Theoretical studies on the electronic structure of NiO solid and its surface and interface will be good for understanding special properties. These studies will also promote the theoretical research for the post transition metal oxides and discover and application for composite compound.With the development of science and technology, the capability of computers becomes more and more advanced, which makes it possible to design new functional materials by the computer simulations. In this paper, our purpose is to simulate the surface and interface of NiO by the computer. With the help of the full potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT), we investigated the electronic structure and the magnetism of the interface and surface structure. The main results of this paper are list as following:The studies on the surface energy and band structures of NiO have been carried out. The energy calculation results indicate that NiO(001) is stable with small surface energy while the NiO(111) is unstable with large surface energy. We can dominate the stability of NiO(001) and NiO(111) surface by control the environment. The DOS and band structure show that the interfacial structures have ferromagnetic properties.The studies on NiO/MgO interface show that: the strain energy of NiO/MgO (001) is larger than that of NiO/MgO (111), while the work of separation of NiO/MgO is smaller that of NiO.MgO (111). So the NiO/MgO (001) is more firmer than NiO/MgO (111).the energy calculation results indicate that NiO/MgO(001) interface has ferromagnetism and the NiO/MgO(111) interface has half- metallic properties. For NiO/MgO(001) and NiO/MgO(111) interface structure, the local magnetic moments were obviously expanded at the interface for Ni atoms compared with the corresponding magnetic moment in bulk NiO. The density of states and band structure show that the interface structure affects the electronic structure.