• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.87-88
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• 2006

The phase transformation behaviors of Ni-Ti shape memory alloys were investigated through a DSC(Differential Scanning Calorimetry). The annealing temperatures were applied from $600^{\circ}C,\;700^{\circ}C,\;800^{\circ}C,\;and\;900^{\circ}C$ for their effects on the phase transformation behaviors. Based on the results of DSC, phase transformation behaviors of shape memory alloys can be predicted by Liang's phase transformation model or Tanaka's phase transformation model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 C
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• pp.440-442
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• 2000

We have successfully fabricated SiC Schottky diodes using Al, Ni, Ti metallization systems. Schottky barrier height and other parameter have been measured by using I-V and C-V technique. The measured barreir heights depend on the metal and measurement techniques used. The barrier heights were 1.85eV(Al), 1.63eV(Ni), 0.97eV(Ti). The Ideality factors were 1.16(Al), 1.07(Ni), 1.05(Ti). Thermal stress tests were performed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.243-244
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• 2006

• 센서학회지
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• 제18권5호
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• pp.343-348
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• 2009

$NiO{\cdot}(Co_{0.25}Mn_{0.75})_2O_3$(Mn-Ni-Co) and $Ba_{0.5}Sr_{0.5}TiO_3$(BST) thick films were screen printed on Pt patterned alumina substrate to investigate the effects of sintering temperature on humidity and temperature sensing properties of ceramic sensors. A raise in sintering temperature increased resistance and B constant of the Mn-Ni-Co temperature sensor. This may have derived from the synergic effects of the reduction in charge carriers caused by the substitution of Co for Mn as well as the formation of microcracks from the difference in thermal expansion coefficients. Dependence of resistance on humidity of the Mn-Ni-Co temperature sensor, however, was not found. BST films sintered at temperatures in the range of $1100^{\circ}C$ to $1150^{\circ}C$ showed excellent humidity sensing properties. The BST humidity sensor was faster in its response than the Mn-Ni-Co temperature sensor. The humidity sensor, however, proved to be unstable under various temperatures, suggesting a need for a temperature stabilizing device. In contrast, the Mn-Ni-Co temperature sensor was stable under humid conditions.

• 한국세라믹학회지
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• 제23권6호
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• pp.52-58
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• 1986

$Pb(Zr_{0.525} Ti_{0.475})O_3$ piezoelectric ceramics both unmodified and doped with NiO were prepared by the conventional oxide techniques using sintering temperature from 900 to to 125$0^{\circ}C$. The difference in densification process between unmodified and NiO doped PZT ceramics was studied by shrinkage vs. firing temperatures and it was caused by increasing defect concentration in calcining process of NiO doped PZT ceramics. And nickel oxide solubility limit for $Pb(Zr_{0.525} Ti_{0.475})O_3$ ceramics is shown to be at the range from 0.2wt% to 0.5wt% from this defect model micro-structures dielectric and piezolectric properties of Nio doped PZT ceramics.

• 한국재료학회지
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• 제17권2호
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• pp.86-90
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• 2007

The organic-capped Ba-Ti-O nanolayers were coated uniformly on spherical Ni particles for multilayer ceramic capacitor (MLCC) applications via the formation of Ti-hydroxide nano-coating layers and their subsequent reaction with Ba-stearate at $180^{\circ}C$. The capping of organic shell on oxide coating layer changed the hydrophilic surface structure into hydrophobic one, which significantly improved the dispersion behavior in hydrophobic solvents such as terpineol and butanol. In addition, the uniform coating of Ba-Ti-O layer was advantageous to prevent Ni oxidation. This method provides a useful chemical route to fabricate organic-soluble Ba-Ti-O coated Ni particles for a highly integrated passive component.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
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• pp.75-78
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• 2004

$Bi_{3.25}Eu_{0.75}Ti_3O_{12}$ (BET) thin films were deposited on the $LaNiO_3$ (LNO (100))/Si and Pt/Ti/$SiO_2$/Si substrates by the metal-organic decomposition method. Structural and dielectric properties of BLT thin films for the applications in nonvolatile ferroelectric random access memories were investigated. Both the structure and morphology of the films were analyzed by x-ray diffraction (XRD) and atomic force microscope (AFM). Even at low temperatures $650^{\circ}C$, the BET thinfilms were successfully deposited on LNO bottom electrode and exhibited (001) and (117) orientation. Compared with the Pt electrode films, the BET thin films on the LNO electrode annealed at $650^{\circ}C$ showed better dielectric constantsand remanent polarization. The BET thin films on the LNO electrode for the annealing temperature of $650^{\circ}C$, the remanent polarization Pr and coercive field were $45.6\;C/cm^2$ and 171 kV/cm, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.338-339
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• 2005

본 연구에서는 $Fe_2O_3$를 첨가한 $Pb(Ni_{1/3}Nb_{2/3})O_3-Pb(Zr_xTi_{1-x})O_3$ 세라믹스에서 Zr/Ti 비 변화에 따른 소결 및 압전, 유전특성을 조사하였다. $0.4Pb(Ni_{1/3}Nb_{2/3})O_3-0.6Pb(Zr_xTi_{1-x})O_3$+0.25Wt% $Fe_2O_3$ 계에서 Zr/(Ti+Zr)비(x)를 0.39에서 0.42까지 변화시킨 조성을 1100 - $1250^{\circ}C$ 온도에서 2시간 소결하여 이의 결정구조 및 미세조직을 분석하였고, 압전, 유전 특성 및 RAINBOW 액츄에이터로의 응용을 조사하였다. $1150^{\circ}C$에서 소결한 0.405 조성(x)에서 유전상수(${\varepsilon}r$) = 4669, 전기기계결합계수(kp) = 0.75, 압전상수($d_{33}$) = 810 pC/N의 우수한 특성 값을 나타내었으며, 닥터블레이드법에 의해 RAINBOW 액츄에이터를 제작하여 변위특성을 조사하였다.

• 폴리머
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• 제33권1호
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• pp.84-90
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• 2009

니티놀(Nitinol) 합금(TiNi)은 혈관 스텐트로서 널리 사용되고 있다. 본 연구에서는 니티놀 합금의 혈액적 합성을 개선시키기 위해서 화학적인 표면개질을 행하였다. 먼저 니티놀의 표면을 금으로 코팅한 다음 시스턴(L-cysteine, C/N)을 화학흡착한 후 신규 합성한 양쪽성 이온 폴리에틸렌글리콜(PEG) (PEG-$N^+-SO_3{^-}$)을 그래프트 시켜서 TiNi-C/N-PEG-N-S를 제조하였다. 양쪽성 이온 PEG가 그래프트된 니티놀의 표면은 ATR-FTIR, ESCA 및 SEM을 통해서 확인하였고 친수성 표면은 물 접촉각의 감소를 통해서 입증하였다. 또한, 단백질 흡착 및 혈소판 점착과 혈액응고시간 측정과 같은 혈액적합성 평가 결과로부터 미처리 니티놀 합금에 비해서 표면개질된 니티놀 합금이 상대적으로 훨씬 우수한 혈액적합성을 나타내었다. 이는 그래프트된 친수성 PEG와 항응혈성 양쪽성 이온의 상승효과에 의해서 혈액적합성을 대폭 개선시킨 것으로 사료된다.

• 한국분말재료학회지
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• 제13권6호
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• pp.396-400
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• 2006

The Ti-Ni alloy nanopowders were synthesized by a levitational gas condensation (LGC) by using a micron powder feeding system and their particulate properties were investigated by x-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) method. The starting Ti and Ni micron powders $150{\mu}m$ were incorporated into the micron powder feeding system. An ingot type of the Ti-Ni ahoy was used as a seed material for the levitation and evaporation reactions. The collected powders were finally passivated by oxidation. The x-ray diffraction experiments have shown that the synthesized powders were completely alloyed with Ti and Ni and comprised of two different cubic and monoclinic crystalline phases. The TEM results showed that the produced powders were very fine and uniform with a spherical particle size of 18 to 32nm. The typical thickness of a passivated oxide layer on the particle surface was about 2 to 3 nm. The specific surface area of the Ti-Ni alloy nanopowders was $60m^2/g$ based on BET method.