基于密度泛函理论的NiAs型MnTe第一原理计算

运用MaterialsStudio 6.0程序CASTEP软件包建立NiAs型MnTe单胞和1×1×10的超胞模型,采用GGA-PBE-TS近似,得出能带结构和态密度曲线。NiAs型MnTe为间接能隙窄带半导体,带隙为0.843eV;MnTe单胞的下价带在-12.5~-10.5eV,是一条二重简并带。在-6~-3.5eV和0.8~2.6eV主要由Mn原子的d态电子贡献,该Mn原子的d电子的有效质量较大,导致强的电子局域性;MnTe1×1×10超胞的帯隙为0.623eV,下价带位于-13~-11eV,对比单胞略微下移;在上价带和导带区域,MnTe超胞d态电子的能带和态密度都比MnTe单胞的变化平稳,整体形成较宽的赝能隙,说明Mn离子的共价性较强。

First-principles calculations on MnTe of NiAs-type structure with density functional theory

The band structure and density of states（DOS） properties were calculated by CASTEP codes of Materials Studio 6.0, which were built as MnTe unit cell and 1×1×10 supercell, using generalized gradient approximation（GGA）. The calculated results show the MnTe is indirect and narrow-band semiconductor, the band gap is 0. 843 eV. The valence band at the under of the energy band diagram, in the region of -12. 5--10. 5 eV, is a double degenerate band. The atom of Mn is consisted of d-electron have a huge of active mass and intense electronic local at the section of - 6 -3.5 eV and 0. 8-2. 6 eV. The band gap of MnTe 1× 1× 10 supercell is 0. 623 eV, and the energy value of the downsite is --11--13 eV. By contrast with MnTe unit cell, there is a small decrease at the interval of --13--11 eV, the energy band and DOS are more stable at the d state. MnTe supercell take the shape of a wide pseudogap, explained Mn ion has a strong covalent.