• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.230-231
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• 2006

In this paper, we examined effects by the binder in manufacturing titanium dioxide film for dye sensitized solar cell. Binder(PEG and PEO) was added the amount of 10-40wt% to commercial $TiO_2$ (P25), Respectively. All of $TiO_2$ film was showed porous structure owing to the addition of binders. But the difference of film's porosity could not be confirmed. The transmittance of $TiO_2$ film was decreased with the increase of binder's amount, generally. In case of 20wt%, however. The transmittance of $TiO_2$ films was showed the highest value.

• 한국표면공학회지
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• 제50권5호
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• pp.392-397
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• 2017

The Young's modulus of a nanoscale titanium (Ti) thin-film was evaluated using a high-speed microcantilever resonating at the megahertz frequency in the present study. A 350 nm thick Ti film was deposited on the surface of a silicon microcantilever, and the morphology of the film was analyzed using the atomic force microscopy. The microcantilever was excited to resonate using an ultrasonic pulser that generates tone burst signals and the resonance frequency shift induced by the deposition of Ti was measured using a Michelson interferometer. The Young's modulus was determined through a modal analysis using the finite element method and the result was validated by the nanoindentation testing, showing good agreement within a relative error of 1.0%. The present study proposes a nanomechanical characterization technique with enhanced accuracy and sensitivity.

• Bulletin of the Korean Chemical Society
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• 제20권8호
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• pp.869-874
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• 1999

In this paper, electrochemical techniques are used to investigate hydrothermal-electrochemically formation of barium titanate (BT) ceramic films. For comparison, the electrochemical behaviors of anodic titanium oxide films formed in alkaline solution were also investigated both at room temperature and in hydrothermal condition at 150.0 ℃. Film structure and morphology were identified by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Titanium oxide films produced at different potentials exhibit different film morphology. The breakdown of titanium oxide films anodic growth on Ti electrode plays an important roles in the formation of BT films. BT films can grow on anodic oxide/metal substrate interface by short-circuit path, and the dissolution-precipitation processes on the ceramic film/solution interface control the film structure and morphology. Based upon the current experimental results and our previous work, extensively schematic proce-dures are proposed to model the mechanism of ceramic film formation by hydrothermal-electrochemical method.

• Corrosion Science and Technology
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• 제22권3호
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• pp.193-200
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• 2023

Titanium alloy (grade-4) is commonly used in industrial and medical applications. To improve its corrosion resistance and biocompatibility for medical use, it is necessary to form a titanium oxide film. In this study, the morphology of the oxide film formed by anodizing Ti-grade 4 using different electrolytes was analyzed. Wetting properties before and after surface modification with SAM coating were also observed. Electrolytes used were categorized as A, B, and C. Electrolyte A consisted of 0.3 M oxalic acid and ethylene glycol. Electrolyte B consisted of 0.1 M NH₄F and 0.1 M H₂O in ethylene glycol. Electrolyte C consisted of 0.07 M NH₄F and 1 M H₂O in ethylene glycol. Samples B and C exhibited a porous structure, while sample A formed a thickest oxide film with a droplet-like structure. AFM analysis and contact angle measurements showed that sample A with the highest roughness exhibited the best hydrophilicity. After surface modification with SAM coating, it displayed superior hydrophobicity. Despite having the thickest oxide film, sample A showed the lowest insulation resistance due to its irregular structure. On the other hand, sample C with a thick and regular porous oxide film demonstrated the highest insulation resistance.

• 한국재료학회지
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• 제19권6호
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• pp.325-329
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• 2009

Titanium dioxide thin films were fabricated as hydrogen sensors and its sensing properties were tested. The titanium was deposited on a $SiO_2$/Si substrate by the DC magnetron sputtering method and was oxidized at an optimized temperature of $850^{\circ}C$ in air. The titanium film originally had smooth surface morphology, but the film agglomerated to nano-size grains when the temperature reached oxidation temperature where it formed titanium oxide with a rutile structure. The oxide thin film formed by grains of tens of nanometers size also showed many short cracks and voids between the grains. The response to 1% hydrogen gas was ${\sim}2{\times}10^6$ at the optimum sensing temperature of $200^{\circ}C$, and ${\sim}10^3$ at room temperature. This extremely high sensitivity of the thin film to hydrogen was due partly to the porous structure of the nano-sized sensing particles. Other sensor properties were also examined.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.815-818
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• 2008

Titanium was oxidized with oxygen plasma and calcinated with rapid thermal annealing for degradation of humic acid dissolved in water. Titania photocatalytic plate was produced by titanium surface oxidized with oxygen plasma by Plasma Enhanced Chemical Vapor Deposition(PECVD). RF-power and deposition condition is controlled under 100 W, 150 W, 300 W and 500 W. Treatment time was controlled by 5 min and 10 min. The film properties were evaluated by the X-ray Photoelectron Spectroscopy (XPS) and X-Ray Diffraction (XRD). From the experimental results, we found the optimal condition of titania film which exhibited good performance. Moreover photocatalytic capacity was about twice better than thermal spray titania film, and also as good as titania powder.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.283-283
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• 2007

Titanium nitride thin films were deposited on $SiO_2$/Si substrate by rf-reactive magnetron sputtering. The structural and electrical properties of the films were investigated with various $N_2/(Ar+N_2)$ flow ratios (nitrogen/argon flow ratio). The resistivity as well as temperature coefficient of resistance (TCR) of the films strongly depends on phase structure. For the films deposited at nitrogen/argon flow ratio of below 5%, the resistivity increased with increasing nitrogen/argon flow ratios. However, the resistivity of the film deposited at nitrogen/argon flow ratio of 7% decreased drastically; it is even smaller than that of metal titanium nitride. A near-zero TCR value of approximately 9 ppm/K was observed for films deposited at nitrogen/argon flow ratio of 3%.

• 한국세라믹학회지
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• 제45권8호
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• pp.472-476
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• 2008

The surface region of commercial stainless steel 304 and 316 plates has been modified through deposition of the multi-layered coatings composed of titanium film ($0.1{\mu}m$) and gold film ($1-2{\mu}m$) by an electron beam evaporation method. XRD patterns of the stainless steel plates deposited with conductive metal films showed the peaks of the external gold film and the stainless steel substrate. Surface microstructural morphologies of the stainless steel bipolar plates modified with multi-layered coatings were observed by AFM and FE-SEM images. The stainless steel plates modified with $0.1{\mu}m$ titanium film and $1{\mu}m$ gold film showed microstructure of grains of under 100 nm diameter. The external surface of the stainless steel plates deposited with $0.1{\mu}m$ titanium film and $2{\mu}m$ gold film represented somewhat grain growth of Au grains in FE-SEM image. The electrical resistance and water contact angle of the stainless steel bipolar plates modified with multi-layered coatings were examined with the thickness of the gold film.

• 공업화학
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• 제17권2호
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• pp.194-200
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• 2006

금속 산화막 공정에 응용하기 위하여 노즐형태 HCP (hollow cathode plasma) RT-MOCVD에 의해 티타늄 산화막을 증착하였다. TTNB (titanium n-butoxide)를 사용하였을 경우 막을 증착한 후 열처리하여야 하지만 titanium ethoxide에 의해 막을 증착하면 일반적으로 수반되는 열처리 공정을 생략하여도 티타늄 산화막이 직접적으로 형성되었다. RF-power 240 watt, 전극과 기판과의 거리가 3 cm, 반응시간 20 min, Ar와 $O_2$의 유량비 1 : 1에서 티타늄과 산소의 조성비가 1 : 2임을 확인할 수 있었다. 따라서 노즐형태 HCP RT-MOCVD에 의해 티타늄 산화막을 열처리 공정 없이 증착되었으며, 저온에서 다양한 금속 산화막 증착 공정에 응용할 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.245-246
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• 2010