• Journal of the Korean Ceramic Society
• /
• v.34 no.4
• /
• pp.373-379
• /
• 1997

A study on the deposition and characterization of BaTiO3 thin films on MgO-buffered Si(100) substrates by sputtering was conducted. The MgO buffer layers were investigated as a function of deposition temperature. At lower substrate temperature, the MgO layers were not fully crystalline, but a crystallized MgO layer with (001) preferred orientation was obtained at the substrate temperature of $700^{\circ}C$. Partially (00ι) or (h00) textured BaTiO3 films were obtained on Si(100) with the MgO buffer layer grown at 700ι. While, randomly oriented BaTiO3 films with large-scale cracks on the surface were made without the MgO layer. The crystallographic orientation, morphology and electrical properties between the BaTiO3 films on Si with and without the MgO layer were compared using the BaTiO3 film on MgO(100) single crystal substrate as a reference system. Also the favorable role of the MgO layer as a buffer for growing of oriented BaTiO3 films on Si substrates was confirmed.

• 한국초전도학회:학술대회논문집
• /
• v.10
• /
• pp.51-55
• /
• 2000

Using modified melt-textured grown targets, YBa$_2$Cu$_3$O$_{7-{\delta}}$ thin films were prepared by pulsed laser deposition technique at the laser energy density from 1 J/cm$_2$ to 4 J/cm$_2$. All the films showed c-axis preferred orientations, however, a-axis outgrowths on the film surface were considerably increased with an increase of the laser energy density. To examine the origin of the a-axis outgrowth formation, the microstructures of films deposited at 2 J/cm$_2$ and 4 J/cm$_2$ were investigated using X-ray diffraction, transmission electron microscopy, and high-resolution electron microscopy. It was shown that a significant number of Y$_2$O$_3$ inclusions were formed during the growth of c-axis oriented films at 4 J/cm$_2$. These inclusions formed nucleation sites for the a-axis outgrowths. It is considered that, due to the unstable growth conditions with a high flux density of incident vapor species and the strain induced by the surrounding c-axis films, the Y$_2$O$_3$ inclusions would prefer the nucleation of α-axis grains.

• Textile Coloration and Finishing
• /
• v.29 no.3
• /
• pp.148-154
• /
• 2017

Many researches have been made on the processing technology of Poly(ethylene terephthalate) (PET), which is widely used for clothing and non-clothing applications. In this study, we coated PET filaments with m-aramid resin to improve heat resistance and antimicrobial properties. In order to enhance adhesion between PET and m-aramid polymer, the adhesive polymer was coated on the PET filaments using a winding speed of 100m/min and then treated with m-aramid. Scanning electron microscopy was used to analyze the surface of the adhesive polymer and m-aramid treated PET filament. The change of initial degradation temperature according to treatment was confirmed by thermogravimetric analysis. Antimicrobial activity analysis using bacterial reduction method showed that PET filament treated with adhesive polymer and m-aramid had an increased antibacterial effect compared to untreated PET filament.

• Journal of Power System Engineering
• /
• v.14 no.5
• /
• pp.41-47
• /
• 2010

티타늄과 티타늄 합금은 재료적 특이성 때문에 심장 혈관 임플란트에서 일반적으로 사용되어 왔다. 일찍이 적용된 예로는 인공심장판막, 심박조율기의 보호케이스, 혈액 순환 장치 등이 있다. 하지만 물질유도혈전증(Material-induced thrombosis)은 혈전폐색에 의해 기인한 기능 손실로 심장혈관 임플란트 장치의 주된 합병증으로 존재하고 있으며, 심장혈관 임플란트의 혈전유전자는 심장혈관장치의 발달에 주된 난관 중 하나로 남아있다. 그리고 텍스처 혈액 접합 물질(Textured blood-contacting material)은 1960년대 초반 이후부터 혈액순환 보조 장치의 임상실험에 사용되고 있다. 접합 물질에 내장된 텍스처 섬유조직 표면은 형성, 성장, 안정적 부착, 생물학적 내벽(neointimal layer) 등 유도 혈액(entrapping blood) 성분에 의해 형성된다. 공동(cavity) 형상의 용해 가능한 미립자를 사용하는 SCPL법(Solvent casting/particulate leaching method)은 티타늄 기질 이전에 형성된 폴리우레탄 위에 텍스처(texture)를 생성하기 위해 사용되었다. 또한 콜라겐의 부동화(不動化)에 의한 공동(cavity)은 혈액 접합면에 잔존하기 위한 내피세포를 고정할 수 있는 효과가 있다. cpTi로 층화된 PU 기소공성(microporous)은 구조적 특성과 혈전증 감소를 위한 생물학적 내벽 사용의 잠재성을 평가하기 위한 세포 공동체 실험을 통해서 평가되었다.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.10a
• /
• pp.106-108
• /
• 2003

We fabricated Ni and Ni-W alloys for use as a substrate in YBCO coated conductor applications and evaluated the effect of W in Ni on texture, microstructure and surface morphology, and hardness of substrate. Pure Ni, Ni-2 at.％W, and Ni-5at.％W alloy substrates were prepared by plasma arc melting, cold rolling, and the recrystallization heat treatment at various temperature (700- 130$0^{\circ}C$). It was observed that Ni-W alloy substrates had stronger cube texture and maintained it at higher annealing temperature, compared to pure Ni substrate : The full-width at half- maximums of in-plane texture was 13.40$^{\circ}$ for Ni substrate and 4.42$^{\circ}$-5.57$^{\circ}$ for Ni-W substrate annealed at 100$0^{\circ}C$. In addition, it was observed that the Ni-W substrate had smaller grain size, shallower boundary depth, and higher hardness, compared to those of pure Ni substrate.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.10a
• /
• pp.55-58
• /
• 2003

We fabricated the textured Ni substrate and evaluated the effects of processing variables on microstructural evolution and texture transformation. Ni-rods as an initial specimen were prepared by two different methods, i.e., powder metallurgy(P/M) and plasma arc melting(PAM) The texture of the substrate was characterized by pole-figure and surface condition was evaluated by atomic force microscopy. It was observed that the texture of substrate made by P/M did not significantly varied with annealing temperature of 800~120$0^{\circ}C$ and the full-width at half-maximums (FWHM) of both in-plane and out-of-plane were 9$^{\circ}$~10$^{\circ}$. On the other hand, the texture of substrate made by PAM was more dependent on the annealing temperature and the FWHMs of in-plane texture was 9$^{\circ}$~13$^{\circ}$ at the temperature range. In addition, twin texture, (221)＜221＞, was formed as the temperature increased further. The grain size of substrate made by P/M was smaller than that made by PAM and this difference was correlated to the microstructure of initial specimens.

• Transactions on Electrical and Electronic Materials
• /
• v.12 no.4
• /
• pp.169-173
• /
• 2011

In this study, Al-N codoped p-type zinc oxide (ZnO) thin films were deposited on Si and homo-buffer layer templates in a mixture of $N_2$ and $O_2$ gas with ceramic ZnO:(2 wt% $Al_2O_3$) as a sputtering target using DC- magnetron sputtering. X-ray diffraction spectra of two-theta diffraction showed that all films have a predominant (002) peak of ZnO Wurtzite structure. As the $N_2$ fraction in the mixed $N_2$ and $O_2$ gases increased, field emission secondary electron microscopy revealed that the surface appearance of codoped films on Si varied from smooth to textured structure. The p-type ZnO thin films showed carrier concentration in the range of $1.5{\times}10^{15}-2.93{\times}10^{17}\;cm^{-3}$, resistivity in the range of 131.2-2.864 ${\Omega}cm$, and mobility in the range of $3.99-31.6\;cm^2V^{-1}s^{-1}$ respectively.

• Journal of the Korean Solar Energy Society
• /
• v.21 no.1
• /
• pp.1-10
• /
• 2001

Polycrystalline silicon(poly-Si) films are deposited on low temperature glass substrate by Hot-CVD(HWCVD). The structural properties of the poly-Si films are strongly dependent on the temperature$(T_w)$. The films deposited at high $T_w$ of $2000^{\circ}C$ have superior crystalline proper average lateral grain sizes are larger than $1{\mu}m$ and there are no vertical grain boundaries. The sur of the high $T_w$ samples are naturally textured like pyramid shape. These large grain size and text surface are believed to give high current density when applied to solar cells. However, the poly films are structurally porous and contains high defect density, by which high concentration of C and O resulted within the films by air-penetration after removed from chamber.

• Progress in Superconductivity and Cryogenics
• /
• v.8 no.3
• /
• pp.37-40
• /
• 2006

Oxide buffer layers for YBCO coated conductors were fabricated using MOD processing and development of microstructure and texture were investigated. A $CeO_2$ buffer layers were formed on RABiTS tape. Acetate-based precursor solution was employed to synthesize the precursor solution. Subsequently, the precursor solution was stabilized and modified with triethanolamine. $CeO_2$ precursor gel film was coated and annealed in $Ar/H_2$ atmosphere at high temperature. An annealed $CeO_2$ film shows mixed orientation with high (001) texturing. It was shown that (111) texture of $CeO_2$ layers were enhanced by multiple coating. This degradation was attributed to development of microcracks in the multiply coated $CeO_2$ films. Also discussed are the synthesis and the characterization of $La_2Zr_2O_7$ (LZO) buffer layers on RABiTS tape. A biaxially textured LZO buffer layer was fabricated with MOD processing method using metal alkoxide based precursor solution. It was shown that the LZO film were epitaxially grown on RABiTS tape and crack-free & uniform surface was obtained after annealing in $Ar/H_2$ atmosphere.

• The Journal of the Korea Contents Association
• /
• v.9 no.4
• /
• pp.34-44
• /
• 2009

Integrating 3D data acquired in multiple views is one of the most important techniques in 3D modeling. However, due to the presence of surface scanning noise and the modification of vertices consisting of surface, the existing integration methods are inadequate to some applications. In this paper, we propose a method of integrating surfaces by using the local surface topology. We first find all boundary vertex pairs satisfying a prescribed geometric condition on adjacent surfaces and then compute 2D planes suitable to each vertex pairs. Using each vertex pair and neighbouring boundary vertices projected to their 2d plane, we produce polygons and divide them to the triangles which will be inserted to empty space between the adjacent surfaces. A proposed method use local surface topology and not modify the vertices consisting of surface to integrate several of surfaces to one surface, so that it is robust and simple. We also integrate the transformed textures to a 2D image plane computed by using a cylindrical projection to composite 3D textured model. The textures will be integrated according to the partition lines which considering attribute of face object. Experimental results on real object data show that the suggested method is simple and robust.