• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.218-221
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• 2004

The electronic state of ZnO doped with Al, Ga and In, which belong to III family elements in periodic table, was calculated using the density functional theory. In this study, the program used for the calculation on theoretical structures of ZnO and doped ZnO was Vienna Ab-initio Simulation Package (VASP), which is a sort of pseudo potential method. The detail of electronic structure was obtained by the describe variational $X{\alpha}(DV-X{\alpha})$(DV-Xa) method, which is a sort of molecular orbital full potential method. The optimized crystal structures obtained by calculations were compared to the measured structure. The density of state and energy levels of dopant elements was shown and discussed in association with properties.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.425-429
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• 2014

Half-metallic nanostructure is highly applicable in the field of Spintronics and electronic device technology. We examine the electronic properties of a ferrocene-based nanowire as a possible candidate for a half-metallic nanostructure using VASP and SIESTA. Ferrocene-based nanowire shows high stability in both binding energy simulation and molecular dynamics (MD) simulation. The density of states (DOS) and the projected DOS of the ferrocene-based nanowire indicate that one-dimensional clustering of ferrocene molecules can be explained because of p-d orbital hybridization between iron and carbon. Half-metallic property and energy dispersion at the Fermi level due to one-dimensional structure is also observed from the DOS results.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.7
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• pp.589-593
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• 2005

The electronic states of ZnO doped with Al, Ga and In, which belong to III family elements in periodic table, were calculated using the density functional theory. In this study, the calculation was performed by two Programs; the discrete variational Xa (DV-Xa) method, which is a sort of molecular orbital full potential method; Vienna Ab-initio Simulation Package (VASP), which is a sort of pseudo potential method. The fundamental mixed orbital structure in each energy level near the Fermi level was investigated with simple model using DV-Xa. The optimized crystal structures calculated by VASP were compared to the measured structures. The density of state and the energy levels of dopant elements were shown and discussed in association with properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.172-173
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• 2005

The electronic state of ZnO doped with Y was calculated using the density functional theory. In this study, the program used for the calculation on theoretical structures of ZnO and doped ZnO was Vienna Ab-initio Simulation Package (VASP), which is a sort of pseudo potential method. The detail of electronic structure was obtained by the descrite variational $X\alpha$ (DV-$X\alpha$) method, which is a sort of molecular orbital full potential method. The optimized crystal structures obtained by calculations were compared to the measured structure. The density of state and energy levels of dopant elements was shown and discussed in association with optical properties.

• Journal of the Korean Chemical Society
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• v.39 no.7
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• pp.564-571
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• 1995

5-Amino-2H-1,2,4-thiadiazoline-3-one has been prepared from 2-thiobiuret through a oxidative cyclization under basic hydrogen peroxide condition. Lactam-lactim tautomerism of 5-amino-2H-1,2,4-thiadiazoline-3-one has been examined by spectroscopic methods and ab initio molecular orbital calculation. These results were shown that 5-amino-2H-1,2,4-thiadiazoline-3-one exists as lactam form. Reaction conditions for alkylating 5-amino-2H-1,2,4-thiadiazoline-3-one with alkyl halides in the presence of various bases were studied in DMF and $H_2O$-THF two phase system. $Li_2CO_3$ base in DMF method gave best result in this investigation. The alkylation has been taken place at N-2 position. The identification of the product is confirmed by spectral data of IR, $^1H$ NMR and $^13C$ NMR and the comparison of authentic sample, 5-amino-2-methyl-1,2,4-thiadiazolidine-3-one, obtained from the oxidative cyclization of 5-methyl-2-thiobiuret.