• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.192-192
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• 2012

The next generation electronics need to not only be smaller but also be more flexible. To meet such demands, electronic devices using two dimensional (2D) atomic crystals like graphene, hexagonal boron nitride (h-BN), molybdenum disulfate ($MoS_2$) and organic thin film have been studied intensely. In this talk, I will demonstrate the $MoS_2$ field effect transistor (FET) toward performance enhancement by insulating h-BN substrate.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.691-693
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• 2007

We report on a highly conductive and stable hole transporting layer comprising of N,N'-di(1- naphthyl)-N,N'-diphenylbenzidine $({\alpha}\;-NPD)$ doped with molybdenum oxide $(MoO_3)$. Compared to the reference device, the device with $MoO_3-doped$ hole transporting material exhibits higher conductivity and thermal stability. The temperature dependence of the current-voltage characteristics are studied for various $(MoO_3)$ doping concentration.

• Molecules and Cells
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• v.46 no.12
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• pp.736-742
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• 2023

NifB, a radical S-adenosylmethionine (SAM) enzyme, is pivotal in the biosynthesis of the iron-molybdenum cofactor (FeMo-co), commonly referred to as the M-cluster. This cofactor, located within the active site of nitrogenase, is essential for the conversion of dinitrogen (N₂) to NH₃. Recognized as the most intricate metallocluster in nature, FeMo-co biosynthesis involves multiple proteins and a sequence of steps. Of particular significance, NifB directs the fusion of two [Fe₄S₄] clusters to assemble the 8Fe core, while also incorporating an interstitial carbide. Although NifB has been extensively studied, its molecular mechanisms remain elusive. In this review, we explore recent structural analyses of NifB and provide a comprehensive overview of the established catalytic mechanisms. We propose prospective directions for future research, emphasizing the relevance to biochemistry, agriculture, and environmental science. The goal of this review is to lay a solid foundation for future endeavors aimed at elucidating the atomic details of FeMo-co biosynthesis.

• Tribology and Lubricants
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• v.10 no.4
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• pp.43-50
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• 1994

In order to elucidate the effects of co-existing additives (S$_{8}$, TBP: Tri butyl phosphate, ZnDTP: Zinc-dialkyl dithiophosphate) and the role of reacted surface film on the friction behavior of MoDTP (molybdenum dialkyl dithiophosphate), a friction experiment using a dual circular pipe edge surface type friction tester and XPS (X-ray photoelectronic spectrum) surface analysis were conducted. Friction reduction with MoDTP lubricant was proved to be greatly influenced by co-existing additive species. It was dependent on the properties of the film formed through the reaction between the additive and the surface. Phosphate film reduced the friction coefficient of MoDTP through suppression of diffusion of Mo compounds towards the metal substrate. On the other hand, sulfate film, which is inherently rich in lattice defects, did not lead to any appreciable friction reduction with MoDTP since the diffusion of the Mo compound towards the metal substrate was not effectively suppressed. With ZnDTP additive, the sulfide film formed through decomposition greatly influenced the lubricating performance of MoDTP. As such, properties of surface films formed from additives were proved to yield significant influence on the lubrication performance of MoDTP.

• Journal of the Korean Chemical Society
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• v.26 no.2
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• pp.81-87
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• 1982

The monooxo-bridged binuclear molybdenum(V) complexes, $Mo_2O_3(NCS)_4(Bipy)_2\;(Bipy = bipyridine),\;Mo_2O_3(NCS)-4(Phen)-2$ (Phen = 1,10-phenanthroline), and $Mo_2O_3(NCS)_4(Ox)_2(OxH)_2$ (Ox = oxinato and OxH = oxine) have been prepared. Their electronic and IR spectra, electric conductivity, and magnetic susceptibility were measured. From the results all of th complexes turned out to be electroneutral dimers with about 0.5 BM, and in the oxine complex, $Mo_2O_3(NCS)_2(Ox)_2(OxH)_2$, the oxine seems to bind partly as monodentate and partly as bidentate molecule.

• Bulletin of the Korean Chemical Society
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• v.25 no.4
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• pp.460-465
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• 2004

Hydrofluoric acid has been used as a novel stripping agent for molybdenum(VI) after its extraction with Cyanex 301. In the extraction step, the effects of parameters such as type and initial concentration of acid, type of diluent, extractant concentration, metal concentration and temperature have been studied. In the stripping step, the effects of various stripping agents on stripping efficiency have been investigated. Hydrofluoric acid has been chosen as an effective stripping agent, and the effects of concentration of hydrofluoric acid, stripping time, volume of hydrofluoric acid and the number of stages of stripping have been studied. Molybdenum(VI) has been effectively separated from a large number of elements in binary mixtures, with a very high tolerance limit. Finally, the optimized method has been extended for the analysis of Mo(VI) in spent molybdenum catalysts.

• Journal of the Korean institute of surface engineering
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• v.55 no.1
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• pp.18-23
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• 2022

Presence of cracks in electrodeposited hard chromium layer, which provide a path of corrosive media to steel substrate, is a serious issue in metal finishing with chromium electroplating. In this study, we added sodium molybdate in an electrolyte for chromium electroplating bath. 130g/L of sodium molybdate in Sargent bath for chromium electroplating causes a codepostion of molybdenum with chromium in a rage of 0.61 ~ 3.14 wt.%. The co-deposited molybdenum enhances the crystallinity of chromium layer, thus the hardness is slightly decreases by the addition of molybdate in electrolyte. However, due to the co-deposition of molybdenum, a crack-free chromium layer could be electrodeposited. Such crack-free chromium layer shows a significantly improved corrosion resistance.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.105-109
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• 2022

For the realization of higher reliable transition metal dichalcogenide layer, molybdenum disulfide was formed on sapphire substrate by direct current sputtering and subsequent rapid thermal annealing process. Unlike RF sputtered MoS₂ thin films, DC sputtered showed no irregular holes and protrusions after annealing process from scanning electron microscope images. From atomic force microscope results, it was possible to investigate that surface roughness of MoS₂ thin films were more dependent on DC sputtering power then annealing temperature. On the other hand, the Raman scattering spectra showed the dependency of significant E¹_2g and A¹_g peaks on annealing temperatures.

• Korean Journal of Crystallography
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• v.13 no.2
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• pp.82-85
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• 2002

From the reaction of cis,cis,trans- [MoBr/sub 2/(CO)/sub 2/(PPh/sub 3/)/sub 2/］with 2,6-dimethylphenyl isocyanide, a molybdenum oxohaloisocyanide compound cis,fac-[Mo(O)Br/sub 2/,(CN-C/sub 6/H/sub 3/,-2,6-Me/sub 2/)sub 3/] (1) was iso-lated. Compound 1 was characterized by spectroscopy (/sup 1/H-NMR, /sup 13/C｛/sup 1/H｝-NMR, IR) and X-ray diffraction. Crystallographic data for 1: triclinic space group P(equation omitted), a=9.172(2) (equation omitted), b ＝ 11.550(3) (equation omitted), c ＝ 15.106(3) (equation omitted), α ＝ 100.44(2)°, β＝ 107.12(2)°, γ＝ 107.83(1)°, Z ＝ 2, R(wR/sub 2/) ＝ 0.0529(0.1344).

• Journal of the Korean Chemical Society
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• v.38 no.2
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• pp.101-107
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• 1994

Some molybdenum(III) and (IV) complexes have been prepared from the reaction of $MoCl_4$·2MeCN with N, P, O-donating ligands and characterized by elemental analysis, infrared and UV-Visible spectroscopy. 3,5-Lutidine, 1,2-phenylenediamine, 8-hydroxyquinoline, 9,10-phenanthrenequinone, triphenylphosphine and 1,2-bis(diphenylphosphino)ethane were chosen as coordinating ligands. Stretching frequencies $\upsilon$ (Mo-Cl) of Mo(IV) appear at higher frequencies than those of Mo(III) complexes due to the increasing oxidation number of metal. $MoCl_4(L)_2$ exhibit one Mo-Cl stretching frequency, whereas Mo$Cl_4$(L^L) exhibit four Mo-Cl stretching frequencies. The number of Mo-Cl stretching frequency suggestes the former complexes have trans($D_{4h}$) and the latter complexes have cis($C_{2v}$) symmetry. Stretching frequency ${\nu}g(C{\equiv}N)$ of acetonitrile in Mo(III) complexes are shifted to about 30 $cm^{-1}$ higher frequency compared with that of a free ligand (2260 $cm^{-1}$). These spectral data indicates that Mo(III) complexes are in the octahedral geometries with the coordinated acetonitrile. Finally each molybdenum(III) and (IV) complexes showed the following formulation; $[MoCl_4(L)_2]$,[Mo$Cl_4$(L^L)], $[MoCl_3(L)_2MeCN]$ and [Mo$Cl_3$(L^L)MeCN].