• Journal of the Korean Vacuum Society
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• v.2 no.4
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• pp.507-514
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• 1993

The solid state reaction of Mo/Si multilayer thin films produced by RF magnetron sputtering technique was examine dusing differential scanning calorimetry (DSC) and x-ray diffraction, and explained in view of two concepts, effective drivig force and effective heat of formation. In constant scanning rate DSC, there were two exothermic peks which corresponded to the formation of h-MoSi2 and t-MoSi2 , respectively. The activation energyfor theformation of h-MoSi2 was 1.5eV , and that of t-MoSi2 was 7.8eV. Nucleation wa stherate controlling mechanism for each of the silicide formation. Amorphous phase was not formed , which was consistent withtheprediction by the concept of effective driving force. h-MoSi2 the first crystalline phase, was considered to have lower interfacial free energy than t-MoSi2 and by increasing temperature it was transformed into more stable t-MoSi2.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.217-218
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• 2000

This paper describes a formation of the Mo-silicide on Mo tip to compare the emission characteristics of the Mo tip. Cone-shaped Mo tip arrays were fabricated and silicidized by evaporating a 15nm-thick a-Si film on Mo tip arrays and annealing it in inert ambient at the temperature of $1000\;^{\circ}C$ for 60 sec. The $Mo_5Si_3$ phase of Mo-silicide was observed through X-ray diffraction (XRD) analysis. Although the gate voltage of the Mo-silicide tip increased by 38 V to obtain the current level of 20 nA/tip, the dependence of emission current on vacuum level was improved.

• Applied Chemistry for Engineering
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• v.4 no.2
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• pp.308-317
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• 1993

The study is related to the synthesis of acrylic acid by selective oxidation of acrolein on Mo-V-W multicomponent mixed oxide catalysts. Mo-V-W-O(WVM), Mo-V-O/Mo-W-O(VM/WM), Mo-W-O/Mo-V-O(WM/VM) and mechanical mixtures of Mo-V-O and Mo-W-O(M-VM+WM) were prepared and characterized by BET, XRD, SEM and EPMA. Catalytic activity of these catalysts was tested in a continuous fixed bed reactor. In WVM catalysts small amount of tungsten added to VM increased surface area and selectivity of acrylic acid, but excess amount of tungsten decreased reaction rate of acrolein and selectivity. VM/WM catalysts, VM supported on WM, showed higher activity and selectivity than WM/VM catalysts where WM is supported on VM. Phase cooperation between WM and VM was observed in mechanical mixture of WM and VM and they showed higher yield than WM or VM.

• Journal of the Korean Chemical Society
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• v.38 no.2
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• pp.160-168
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• 1994

Pentadentate Schiff base molybdenum(Ⅴ) complexes such as [Mo(Ⅴ)O(Sal-DET)(NCS)] and [Mo(Ⅴ)O(Sal-DPT)(NCS)] were synthesized by Sabat method. The structure of these complexes were identified by elemental analysis, spectroscopy, and thermogravimetric analysis(T.G.A.). It was found that the mole ratio of Schiff base ligand to the complexes was found to be 1 : 1. The redox processes of the complexes were investigated by cyclic voltammetric and differential pulse polarographic technique in nonaqueous solvent containing 0. 1 M tetraethyl ammonium perchlorate(TEAP) as supporting electrolyte at glassy carbon electrode. It was found that diffusion controlled reduction processes of four steps with one electron were 2Mo(Ⅴ)$\rightleftarrow^{e-}$ Mo(Ⅴ)Mo(Ⅳ) $\longrightarrow^{e-}$ 2Mo(Ⅳ), Mo(Ⅳ) $\longrightarrow^{e-}$ Mo(Ⅲ) $\longrightarrow^{e-}$ Mo(Ⅱ)

• Journal of Surface Science and Engineering
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• v.53 no.6
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• pp.343-350
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• 2020

The degradation of mechanical properties of nitride coatings to steel substrates is one of the main challenges for industrial applications. In this study, plasma nitriding treatment was used in order to increase the mechanical properties of Mo-Cu-N coating to the H13 tool steel. The nanostructured Mo-Cu-N coating was deposited using pulsed DC magnetron sputtering method with a single alloy Mo-Cu target. Mechanical properties of MoN-Cu coated samples after nitriding were found to be relatively better than non-nitrided MoN-Cu coating.

• Applied Science and Convergence Technology
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• v.26 no.5
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• pp.110-113
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• 2017

The two-dimensional layered $MoS_2$ has high mobility and excellent optical properties, and there has been much research on the methods for using this for next generation electronics. $MoS_2$ is similar to graphene in that there is comparatively weak bonding through Van der Waals covalent bonding in the substrate-$MoS_2$ and $MoS_2-MoS_2$ heteromaterial as well in the layer-by-layer structure. So, on the monatomic level, $MoS_2$ can easily be exfoliated physically or chemically. During the $MoS_2$ field-effect transistor fabrication process of photolithography, when using water, the water infiltrates into the substrate-$MoS_2$ gap, and leads to the problem of a rapid decline in the material's yield. To solve this problem, an epoxy-based, as opposed to a water-based photoresist, was used in the photolithography process. In this research, a hydrophobic $MoS_2$ field effect transistor (FET) was fabricated on a hydrophilic $SiO_2$ substrate via chemical vapor deposition CVD. To solve the problem of $MoS_2$ exfoliation that occurs in water-based photolithography, a PPMA sacrificial layer and SU-8 2002 were used, and a $MoS_2$ film FET was successfully created. To minimize Ohmic contact resistance, rapid thermal annealing was used, and then electronic properties were measured.

• Korean Journal of Materials Research
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• v.31 no.2
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• pp.92-96
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• 2021

We report the growth and enhanced photoelectrochemcial (PEC) water-splitting reactivity of few-layer MoS2 nanosheets on TiO2 nanowires. TiO2 nanowires with lengths of ~1.5 ~ 2.0 ㎛ and widths of ~50~300 nm are synthesized on fluorine-doped tin oxide substrates at 180 ℃ using hydrothermal methods with Ti(C4H9O)4. Few-layer MoS2 nanosheets with heights of ~250 ~ 300 nm are vertically grown on TiO2 nanowires at a moderate growth temperature of 300 ℃ using metalorganic chemical vapor deposition. The MoS2 nanosheets on TiO2 nanowires exhibit typical Raman and ultraviolet-visible light absorption spectra corresponding to few-layer thick MoS2. The PEC performance of the MoS2 nanosheet/TiO2 nanowire heterostructure is superior to that of bare TiO2 nanowires. MoS2/TiO2 heterostructure shows three times higher photocurrent than that of bare TiO2 nanowires at 0.6 V. The enhanced PEC photocurrent is attributed to improved light absorption of MoS2 nanosheets and efficient charge separation through the heterojunction. The photoelectrode of the MoS2/TiO2 heterostructure is stably sustained during on-off switching PEC cycle.

• Journal of Korea Foundry Society
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• v.10 no.3
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• pp.225-234
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• 1990

Spheroidal graphite cast irons which are Fe-3%C-(4－6)%Si-(0－0.5)%Mo were studied to improve not only heat resistance but also mechanical properties. With increasing Mo content, the graphitization was decreased and carbide volume fraction was increased. The graphite spheroidization ratio was not decreased in Fe-3%C-6%Si-Mo system cast iron with increasing Mo content, but that was decreased in Fe-3%C-4%Si-Mo system and Fe-3%C-5%Si-Mo system cast irons. Hardness was increased with the Si and Mo contents. At constant Si content, tensile strength was increased with increasing Mo content, but that was decreased at 6%Si. In the experiment of oxidation, weight gain was decreased as the Si and/or Mo content increased, but increased at 1.5%Mo content.

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.6
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• pp.34-41
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• 1984

MOEN/MO double layer which is to be used It)r the RMOS (refractory metal oxide semiconductor) gate material has been fabricated by means of low temperature reactive sputtering in N2 and Ar mixture. Good Mo2N film was obtained in the volumetric mixture of Ar:N2=95:5. The sheet resistance of the fabricated Mo7N film was about 1.20 - 1.28 ohms/square, which is about an order of magnitude lower than that of polysilicon film, and this would enable to improve the operational speed of devices fabricated with this material. When PSG (phosphorus silicate glass) was used as impurity diffusion source for the source and drain of the RMOSFET in the N2 atmosphere at about 110$0^{\circ}C$, the Mo2N was reduced to Mo resulting in much smaller sheet resistance of about 0.38 ohm/square. The threshold voltage of the RMOSFET fabricated in our experiment was - 1.5 V, and both depletion and enhancement mode RMOSFETs could be obtained.

• Journal of Sensor Science and Technology
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• v.24 no.3
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• pp.151-154
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• 2015

The gas sensing characteristic of $MoS_2-MoO_2$ composite yolk-shell spheres were investigated. $MoO_3$-carbon composite spheres were prepared by ultrasonic spray pyrolysis of aqueous droplets containing Mo-source and sucrose in nitrogen, which were converted into $MoO_3$ yolk-shell spheres by heat treatment at $400^{\circ}C$ in air. Subsequently, $MoS_2-MoO_2$ composite yolk-shell spheres were prepared by the partial sulfidation of $MoO_3$. The $MoS_2-MoO_2$ composite yolk-shell spheres showed relatively low and irreversible gas sensing characteristics at < $200^{\circ}C$. In contrast, the sensor showed high and reversible response (S=resistance ratio) to 5 ppm $NO_2$ (S=14.8) at $250^{\circ}C$ with low cross-responses (S=1.17-2.13) to other interference gases such as ethanol, CO, xylene, toluene, trimethylamine, $NH_3$, $H_2$, and HCHO. The $MoS_2-MoO_2$ composite yolk-shell spheres can be used as reliable sensors to detect $NO_2$ in a selective manner.