Ab initio study of oxygen-vacancy LaAlO3（001） surface

Density functional theory is used to investigate the surface structures and the energies of two possible terminated LaAlO3 （001） surfaces with oxygen vacancies, i.e. LaO- and AlO2-terminated surfaces. The large displacements of ions, deviated from their crystalline sites, can lead to the formation of the surface rumpling. From thermodynamics analysis, the AlO2-terminated surface with oxygen-vacancies is less stable than the LaO-terminated one. Some states in the gap lie under the Fermi level by about -1eV in the LaO-terminated surface with oxygen vacancies. For the AlO2- terminated oxygen-vacancy surface, some O 2p states move into the mid-gap region and become partially unoccupied. The two types of termination surfaces exhibit conduction related to oxygen vacancies. Our results can contribute to the application of LAO films to high dielectric constant materials.

Ab initio study of oxygen-vacancy LaAlO2(001) surface

Density functional theory is used to investigate the surfacestructures and the energies of two possible terminated LaAlO真空;表面条件;密度功能计算;电子学oxygen vacancy, surfaceconduction, density functional calculationProject supported by the NationalScience Fund for distinguishedYoung Scholars of China (Grant No 50425207).3/8/2007 12:00:00 AM9/4/2007 12:00:00 AMDensity functional theory is used to investigate the surface structures and the energies of two possible terminated LaAlO3 （001） surfaces with oxygen vacancies, i.e. LaO- and AlO2-terminated surfaces. The large displacements of ions, deviated from their crystalline sites, can lead to the formation of the surface rumpling. From thermodynamics analysis, the AlO2-terminated surface with oxygen-vacancies is less stable than the LaO-terminated one. Some states in the gap lie under the Fermi level by about -1eV in the LaO-terminated surface with oxygen vacancies. For the AlO2- terminated oxygen-vacancy surface, some O 2p states move into the mid-gap region and become partially unoccupied. The two types of termination surfaces exhibit conduction related to oxygen vacancies. Our results can contribute to the application of LAO films to high dielectric constant materials.State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, China;State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, China;State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, China;State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, China;State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, ChinaCorresponding author. E-mail： junzhu@uestc.edu.cn/qk/85823A/200802/26433271.html6170P, 7320A, 7115MDensity functional theory is used to investigate the surfacestructures and the energies of two possible terminated LaAlO真空;表面条件;密度功能计算;电子学oxygen vacancy, surfaceconduction, density functional calculationProject supported by the NationalScience Fund for distinguishedYoung Scholars of China (Grant No 50425207).3/8/2007 12:00:00 AM9/4/2007 12:00:00 AMDensity functional theory is used to investigate the surface structures and the energies of two possible terminated LaAlO3 （001） surfaces with oxygen vacancies, i.e. LaO- and AlO2-terminated surfaces. The large displacements of ions, deviated from their crystalline sites, can lead to the formation of the surface rumpling. From thermodynamics analysis, the AlO2-terminated surface with oxygen-vacancies is less stable than the LaO-terminated one. Some states in the gap lie under the Fermi level by about -1eV in the LaO-terminated surface with oxygen vacancies. For the AlO2- terminated oxygen-vacancy surface, some O 2p states move into the mid-gap region and become partially unoccupied. The two types of termination surfaces exhibit conduction related to oxygen vacancies. Our results can contribute to the application of LAO films to high dielectric constant materials.State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, China;State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, China;State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, China;State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, China;State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, ChinaCorresponding author. E-mail： junzhu@uestc.edu.cn/qk/85823A/200802/26433271.html6170P, 7320A, 7115MDensity functional theory is used to investigate the surfacestructures and the energies of two possible terminated LaAlO真空;表面条件;密度功能计算;电子学oxygen vacancy, surfaceconduction, density functional calculationProject supported by the NationalScience Fund for distinguishedYoung Scholars of China (Grant No 50425207).3/8/2007 12:00:00 AM9/4/2007 12:00:00 AMDensity functional theory is used to investigate the surface structures and the energies of two possible terminated LaAlO3 （001） surfaces with oxygen vacancies, i.e. LaO- and AlO2-terminated surfaces. The large displacements of ions, deviated from their crystalline sites, can lead to the formation of the surface rumpling. From thermodynamics analysis, the AlO2-terminated surface with oxygen-vacancies is less stable than the LaO-terminated one. Some states in the gap lie under the Fermi level by about -1eV in the LaO-terminated surface with oxygen vacancies. For the AlO2- terminated oxygen-vacancy surface, some O 2p states move into the mid-gap region and become partially unoccupied. The two types of termination surfaces exhibit conduction related to oxygen vacancies. Our results can contribute to the application of LAO films to high dielectric constant materials.State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, China;State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, China;State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, China;State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, China;State Key Laboratory of Electronic Thin Films andIntegrated Devices, University of Electronic Science and Technologyof China,Chengdu 610054, ChinaCorresponding author. E-mail： junzhu@uestc.edu.cn/qk/85823A/200802/26433271.html6170P, 7320A, 7115MDensity functional theory is used to investigate the surfacestructures and the energies of two possible terminated LaAlO₃(001) surfaces with oxygen vacancies, i.e. LaO- andAlO₂-terminated surfaces. The large displacements of ions,deviated from their crystalline sites, can lead to the formation ofthe surface rumpling. From thermodynamics analysis, theAlO₂-terminated surface with oxygen-vacancies is less stablethan the LaO-terminated one. Some states in the gap lie under theFermi level by about --1eV in the LaO-terminated surface with oxygenvacancies. For the AlO₂-terminated oxygen-vacancy surface, someO 2p states move into the mid-gap region and become partiallyunoccupied. The two types of termination surfaces exhibit conductionrelated to oxygen vacancies. Our results can contribute to theapplication of LAO films to high dielectric constant materials.