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Study on Half-metallic Ferromagnetism of ZKCa (Z= Ge, Sn) and Interface CrSb/NaCl

Author: SongMingHui
Tutor: YaoKaiLun
School: Huazhong University of Science and Technology
Course: Condensed Matter Physics
Keywords: Density functional theory Half-metallic ferromagnet Half H?usler Interface Density of states
CLC: O482.523
Type: Master's thesis
Year: 2009
Downloads: 16
Quote: 0
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Abstract


In conventional electronic devices are electronic charge as an information carrier , which will produce a lot of heat , so that the device becomes very limited degree of integration . Electron's spin but they can overcome such drawbacks. Semi-metallic magnetic materials is based on the role of electron spin new materials have been used in magnetic devices, and because it has a high spin polarization can also be used as a semiconductor spin injection source . Now, with the continuous improvement and density functional theory calculations with computer speeds continue to increase , making the theoretical study of the properties of materials ( including semi- metallic properties ) as possible, this also greatly reduces the cost of experimental research . Theoretical study of half-metallic ferromagnet main means of density functional theory and the full- potential method pseudopotential plane wave method . First, we use the full-potential linearized augmented plane wave method and the generalized gradient approximation forecasts and a half without a transition metal compound GeKCa and SnKCa H?usler has a half -metallic ferromagnetism and 100% spin polarization . GeKCa and semi- metallic gaps SnKCa were 0.32eV and 0.33eV, and the half-metallic ferromagnetic will remain unchanged until the lattice constant of the equilibrium lattice constant is compressed to 10% and 13%. Half-metallic ferromagnetism is mainly produced in Ge ( or Sn) p electron spin polarization states . Then , the use of LDA U discussion CrSb (001) / NaCl (100) nature of the interface , the interface is formed we found that there are two combinations, but not a semi- metallic in nature. Case (b) , the interface has the lowest total energy , the total magnetic moment of each supercell 9.88μB, spin polarization was 98.8% . Semi- metallic interface disappears because the interface caused by the charge transfer .

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CLC: > Mathematical sciences and chemical > Physics > Solid State Physics > Solid nature of the > Magnetic properties > All kinds of magnetic > Ferromagnetic
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