• The Korean Journal of Ceramics
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• v.3 no.1
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• pp.13-17
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• 1997

It is identified that the diamond films grown o bias-treated (100) silicon showed different surface morphologies and film textures according to the initial applied dc bias voltage at the same growth condition. The highly oriented diamond film (HODF) was successfully grown on -200 V bias-treated silicon substrate in which the heteroepitaxial relation of $(100)_{dimond}//(100)_{si}\; and\; [110]_{diamond}//[110]_{si}$ was identified. On the contrary, the heteroepitaxial relation was considerably disturbed in the samples bias-voltage was a key factor in growing the highly oriented diamond film on (100) silicon substrate. Considering the experimental results, we proposed a new model about heteroepitaxial diamond growth on silicon, in which 9 diamond unit cell are matched with 4 silicon cells and the bond covalency of both atoms is satisfied via the intermediate layer at the interface as well.

• Journal of the Korean Society of Safety
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• v.14 no.3
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• pp.110-119
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• 1999

This study was conducted to invent brake of non-steel material without using asbestos and disc pad added $ZrSiO_4$ was made. The physical properties and friction characteristics were investigated by varying methods. The physical properties were inspected of shear strength, hardness, heat expansion, specific gravity, % of gashole, thickness variation, weight variation and pH variation. The friction stability was measured by friction coefficient on variations of speed, temperature and deceleration condition. It was found that the physical properties were in general excellent. According to the friction characteristics tests, $ZrSiO_4$ had an abrasive property. As a results, the friction materials containing $ZrSiO_4$ 3~5vol% showed better resistance to fading and improved friction stability than the materials without ZrSiO$_4$.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.1
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• pp.41-47
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• 1992

In SFB Process, after 110$0^{\circ}C$ annealing in wet OS12T(95$^{\circ}C$ HS12TO bubbling) atmosphere, the existence of the interfacial oxide film in micro-gap at Si-Si bonding interface was identified. The angle lapping/staining and SEM morphologies of bonding interface showed that the growing behavior of interfacial oxide made a contribution to eliminate the micro-gaps having a width of 200-300$\AA$. In case of the diodes composed of p-n wafer pairs made by SFB processes, the annealed one in wet OS12T atmosphere exhibited a dielectric breakdown phenomena of interfacial oxide at 37-40 volts d.c.

• Korean Journal of Materials Research
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• v.7 no.7
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• pp.604-607
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• 1997

SiO$_{2}$를 첨가한 Cr$_{2}$O$_{3}$의 전기전도도와 미세구조를 산소분압, 온도, 그리고 SiO$_{2}$첨가량에 따라 측정하였다. 입자직경은 1$\mu\textrm{m}$보다 작다. 순수한 Cr$_{2}$O$_{3}$의 전기전도도는 산소분압과 온도가 증가함에 따라 증가하였으며 110$0^{\circ}C$부터 진성 영역이 나타났다. Cr$_{2}$O$_{3}$의 전기전도도는 SiO$_{2}$첨가로 감소하지만, 산소분압에 따른 변화는 SiO$_{2}$첨가와 무관하다.

• Journal of the Korean Magnetics Society
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• v.16 no.6
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• pp.283-286
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• 2006

We have studied the role of ${\alpha}-Al_{2}O_{3}$ buffer layer as a diffusion barrier in the Ba-ferrite/$SiO_{2}$ magnetic thin films for high-density recording media. In the interface of amorphous Ba-ferrite $(1900-{\AA}-thick)/SiO_{2}$ thin film during annealing, the interfacial diffusion started to occur at ${\sim}700^{\circ}C$. As the annealing temperature increased up to $800^{\circ}C$, the interfacial diffusion abruptly proceeded resulting in the high interface roughness and the deterioration of the magnetic properties. In order to control the interfacial diffusion at the high temperature, we introduced ${\alpha}-Al_{2}O_{3}$ buffer layer ($110-{\AA}-thick$) in the interface of Ba-ferrite/$SiO_{2}$ thin film. During the annealing of Ba-ferrite/${\alpha}-Al_{2}O_{3}/SiO_{2}$ thin film even at ${\sim}800^{\circ}C$, the interface was very smooth. The magnetic properties, such as saturation magnetization and intrinsic coercivity, were also enhanced, due to the inhibition of interfacial diffusion by the ${\alpha}-Al_{2}O_{3}$ buffer layer. Our study suggests that the ${\alpha}-Al_{2}O_{3}$ buffer layer act as a useful interfacial diffusion barrier in the Ba-ferrite/$SiO_{2}$ magnetic thin films.

• Proceedings of the Korean Magnestics Society Conference
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• 2010.06a
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• pp.165-166
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• 2010

• Proceedings of the Korean Vacuum Society Conference
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• 2002.06a
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• pp.182-182
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• 2002

• Journal of the Korean Society of Industry Convergence
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• v.18 no.2
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• pp.110-118
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• 2015

In this study, it is designed and used the test engine bed which is installed with turbocharger, and in addition to equipped using by oxygen adder. It has been controlled the oxygen volumetric fraction of intake air chrge, and supercharged flow rate into the cylinder of SI 4-stroke engine, and then, has been analyzed engine performance, combustion characteristics, and exhaust emission as analysis parameters. The tested parameters were the oxygen fraction and the variation of engine speed and air-fuel ratio.

• Journal of Electrical Engineering and information Science
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• v.2 no.5
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• pp.108-113
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• 1997

In this paper, the optimum condition of (110) Si etching with the potassium hydroxide(KOH) etchant is presented. Although several researches on (110) Si anisotropic etching have been studied, there has been lack of effects of mask quality and etching conditions on the selectivity and the roughness o the etched surface. Three kinds of masks (film, emulsion and E-beam mask) were used in order to verify the effect of etching properties. Anisotropic bulk etching depends on the crystalline orientation and the concentration and temperature of the etchant. In order to investigate the effect of etching conditions on selectivity and the roughness of the etched surface, the concentration of the etchant was varied from 35 to 45 per cent in weight with increments by 5 per cent and the temperature was changed from 70 to 90$^{\circ}C$ with increments by 10$^{\circ}C$. The combination of the temperature of 70$^{\circ}C$ and the concentration of 40wt.% was found to be the optimum etching condition for high selectivity. Etched surfaces show minimum surfaces show minimum surface roughness at a temperature of 80$^{\circ}C$ and a concentation of 40wt.%. Comb structures with various comb widths were fabricated and the lengths of the combs wree measured with several etching time durations. A micro comb structure 525$\mu\textrm{m}$ high was fabricated for MEMS application.

• Journal of the Korean institute of surface engineering
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• v.39 no.3
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• pp.110-114
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• 2006

In this work, comparative studies on microstructure and mechanical properties between $Mo_2N$ and Mo-Si-N coatings were conducted. Ternary Mo-Si-N coatings were deposited on AISI D2 steel substrates by a hybrid method, where AIP technique was combined with a magnetron sputtering technique. Instrumental analyses of XRD, HRTEM, and XPS revealed that the Mo-Si-N coatings must be a composite consisting of fine $Mo_2N$ crystallites and amorphous $Si_3N_4$. The hardness value of Mo-Si-N coatings significantly increased from 22 GPa of $Mo_2N$ coatings to about 37 GPa with Si content of 10 at.% due to the refinement of $Mo_2N$ crystallites and the composite microstructure characteristics. The average friction coefficient of the Mo-Si-N coatings gradually decreased from 0.65 to 0.4 with increasing Si content up to 15 at.%. The effects of Si content on microstructure and mechanical properties of Mo-N coatings were systematically investigated.