• 한국재료학회지
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• 제19권4호
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• pp.207-211
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• 2009

In this study, we attempted to develop a convenient aluminizing process, using Al-Ti mixed slurry as an aluminum source, to control the Al content of the aluminized layer as a result of a one-step process and can be widely adopted for coating complex-shaped components. The aluminizing process was carried out by the heat treatment on disc and rod shaped S45C steel substrates with Al-Ti mixed slurries that were composed of various mixed ratios (wt%) of Al and Ti powders. The surface of the resultant aluminized layer was relatively smooth with no obvious cracks. The aluminized layers mainly contain an Fe-Al compound as the bulk phase. However, the Al concentration and the thickness of the aluminized layer gradually decrease as the Ti proportion among Al-Ti mixed slurries increases. It has also been shown that the Al-Ti compound layer, which formed on the substrate during heat treatment, easily separates from the substrate. In addition, the incorporation of Ti into the substrate surface during heat treatment was not observed.

• 분석과학
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• 제19권5호
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• pp.376-382
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• 2006

In this work, pitch/activated carbon/$TiO_2$ composite were prepared by $CCl_4$ solvent method with different mixing ratios. The BET surface area of pitch/activated carbon/$TiO_2$ composite has a significantly increase with increasing activated carbon content in pitch/activated carbon/$TiO_2$ composite. The surface structure and elemental compositions of the composite were studied by SEM and EDX, respectively. The SEM results were presented to the characterization of porous texture on the pitch/activated carbon/$TiO_2$ composite. And EDX data was shown the presence of C, O, S, Ti and other elements. The structural properties of the composite were studied in XRD measurements. The $TiO_2$ crystal phases of the pitch/activated carbon/$TiO_2$ composite had lots of rutile-type structure which transforms from anatase-type with a little of anatase-type structure. The photocatalytic activities of the composite were evaluated using a photo-decomposition method under UV lamp. The pitch/activated carbon/$TiO_2$ composites were observed better photocatalytic activity than that of pristine $TiO_2$.

• 대한전자공학회논문지SD
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• 제39권12호
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• pp.1008-1015
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• 2002

분극처리 없이 제작한 lanthanum-modified lead titanate (PLT) 박막의 초전특성에 대한 변조 주파수 의존성을 dynamic method를 이용하여 조사하였다. La이 10mo1% 첨가된 Pb/sub l-x/La/sub x/Ti/sub l-x/4/O₃ (h=0.1) (PLT(10)) 박막을 Pt/TiO/sub x//SiO₂/Si 기판위에 acetate 계 precursor 을 이용한 sol-gel 법으로 제작하였다. 제작된 PLT(10) 박막은 비교적 우수한 유전특성을 보였다. 초전계수 (p) 는 주파수 의존성이 없이 6.6×10/sup -9/ C/㎠·K 을 나타내었다. 이를 이용하여 구한 전압감도와 비검출능을 위한 재료평가지수는 각각 1.03×10/sup -11/ C·㎝/J 과 1.46×10/sup -9/C·㎝/J 로 나타났다. 제작된 PLT(10) 박막 초전형 적외선 센서는 주파수 8Hz 에서 5.15v/w 의 전압감도 (Rv)를 가지며, 잡음등가전력 (NEP) 과 비검출능 (D/sup */) 은 동일한 주파수 100Hz 에서 각각 9.93×10/sup -8/W/Hz/sup 1/2/와 1.81×10/sup 6/cm·Hz/sup 1/2//W 의 최소값과 최대값을 나타내었다. 이와 같은 특성들은 PLT(10) 박막이 초전형 적외선 센서의 감지물질로 매우 적합함을 나타낸 것이다.

• Transactions on Electrical and Electronic Materials
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• 제1권1호
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• pp.17-21
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• 2000

In order to investigate the dependence of a content in lead lanthanum titanate (PLT) films and heat treatment, sol-gel process has been used. Four types of PLT thin films with the chemical formula, Pb$\_$1-x/ La$\_$x/Ti$\_$1-x/4/O$_3$(X=18, 21, 24 and 28 mole %) have been fabricated on Pt/Ti/SiO$_2$/Si multi-layers and ITO/glass substrates, The post-annealing temperature in the range of 400~700 $\^{C}$ is applied for the formation of perovskite structure in PLT films. The structureal, electrical and optical properties of PLT film with the addition of La content are estimated. The films orientation and surface structure of films are studied by XRD (X-ray diffraction) and SEM(scanning electron microscopy). The P-E hysteresis loop become narrower with increasing La content. The average transmittance of the films is about 80%.

• 한국진공학회지
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• 제7권2호
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• pp.127-134
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• 1998

스테인레스강은 내식성이 우수해서 많은 용도로 사용되고 있다. 스테인레스강의 내 식특성과 함께 장식용으로 적당한 색상을 부역하기 위한 여러 방법으로 시도되고 있다. 본 연구에서는 DC amgnetron sputtering장치를 사용하여 스테인레스강의 표면에 TiN(C,O,H) 코팅층을 코팅한 후, 집합조직과 색상에 미치는 산소, 수소, 아세칠렌가스의 영향에 관한 연 구를 수행하였다. 수소와 아세칠렌이 첨가됨에 따라 (220)집합조직은 (200)거쳐서 (111)으로 변화하였고, 아세칠렌이 더욱 증가되면 (111)집합조직을 나타내었다. 산소의 첨가는 (111)을 거쳐 (200)으로 변화시켰다. TiN의 색상은 산소의 첨가에 따라 황금색으로부터 회색을 거쳐 녹색으로 변화하였다. 아세칠렌의 첨가는 분홍색을 거쳐서 회색으로 변화하였다. 반사율은 수소의 첨가에 따라 단파장의 영역에서 증가하였고, 산소와 아세칠렌의 첨가에 따라 감소하 였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.104-107
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• 2001

The fabricated La-modified lead titanate (PLT) thin flim without paling treatment was investigated for modulation frequency dependence of pyroelectric properties by the dynamic method. $Pb_{1-x}La_{x}Ti_{1-x/4}O_{3}$ PLT (x=0.1) thin film having 10 mol% La content was deposited on a $Pt/TiO_{x}/SiO_{2}/Si$ substrate by sol-gel method. The PLT(10) thin film exhibits a relatively excellent dielectric property. The pyroelectric coefficient (p) of the PLT(10) thin film is $6.6{\times}10^{-9}C/cm_{2}\cdot K$ without frequency dependence. The figure of merits for the voltage responsivity and specific detectivity are $1.03{\times}10^{-11}C\cdot cm/J$ and $1.46\times 10^{-9}C\cdot cm/J$, respectively. The PLT(10) thin film has voltage responsivity (Rv) of 5.15 V/W at 8 Hz. Noise equivalent power (NEP) and specific detectivity (D*) of the PLT(10) thin film are$9.93{\times}10^{-8}W/Hz^{1/2}$ and $1.81\times 10^{6}cmHz^{1/2}/W$ at the same frequency of 100 Hz, respectively. The results means that PLT thin film having 10 mol % La content is suitable for the sensing materials of pyroelectric IR sensors.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.104-107
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• 2001

The fabricated La-modified lead titanate (PLT) thin flirt without poling treatment was investigated for modulation frequency dependence of pyroelectric properties by the dynamic method. $Pb_{1-x}La_{x}Ti_{1-x/4}O_3$PLT (x=0.1) thin film having 10 mol% La content was deposited on a Pt/$TiO_{x}$/$SiO_2$/Si substrate by sol-gel method. The PLT(10) thin film exhibits a relatively excellent dielectric property. The pyroelectric coefficient (p) of the PLT(10) thin film is 6.6 x $10^{-9}$C/$\textrm{cm}^2$.K without frequency dependence. The figure of merits for the voltage responsivity and specific detectivity are 1.03${\times}$$10^{-11}$/C.cm/J and 1.46 x $10^{-9}$C.cm/J, respectively. The PLT(10) thin film has voltage responsivity ($R_{V}$) of 5.15 V/W at 8 Hz. Noise equivalent power (NEP) and specific detectivity (D＊) of the PLT(10) thin film are 9.93 x $10^{-8}$W/Hz$^{1/2}$ and 1.81 x $10^{6}$ cmHz$^{1/2}$/W at the same frequency of 100 Hz, respectively. The results means that PLT thin film having 10 mol % La content is suitable for the sensing materials of pyroelectric IR sensors.

• 대한금속재료학회지
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• 제50권4호
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• pp.285-292
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• 2012

Hot ductility behavior of precipitation-hardened low-carbon iron alloys containing 0.02 wt% Ti and 0.05 wt% Nb was characterized by a hot tensile stress test. Carbon (0.05, 0.1, 0.25 wt%) and boron (0.002 wt%) contents were varied to study the effect of precipitates on the high-temperature embrittlement of the alloys in the temperature range of $600{\sim}800^{\circ}C$. Ductility loss was observed at $700^{\circ}C$ for the tested alloys. The cause of the ductility loss was mainly attributed to the carbides and ferrite films formed at the grain boundaries during deformation. Although the carbon content tended to raise the total fraction of Nb (C, N), the precipitates were formed mostly in the grain interior as the precipitation temperature was raised above the deformation temperature by the high carbon content. Hence, carbon in excess suppressed the hot ductility loss. Meanwhile, boron addition improved the hot ductility of the alloys. The improvement is likely due to the boron atoms capturing carbon atoms and thus retarding the carbide formation.

• 한국세라믹학회지
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• 제31권6호
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• pp.623-628
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• 1994

TiO2-SiO2 homogeneous sol was prepared by means of complexing titanium iso-propoxide with acetylacetone. Crack-free, monolithic binary TiO2-SiO2 aerogels were obtained by evacuating the solvent under the pressure of 2,200 psi at 28$0^{\circ}C$, which was determined as a supercritical condition. The microstructure of the binary aerogels was observed to be finer and more homogeneous as the Ti content decreased. The microstructure was related to the optical transition of aerogels from opaque to transluscent.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.36-36
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• 2007

$R_2O_3$(R=Bi, B)-RO(R=Ba, Zn)를 주성분으로 하는 Pb-free유리프리트에 높은 굴절률을 가지고 있는 $TiO_2$ filler를 첨가하여 PDP용 백색유전체를 제조하였다. $TiO_2$ type, 함량에 따른 백색유전체로의 반사율 및 유전 특성을 조사하였다. 백색유전체를 소성한 결과 rutile과 anatase를 중량비로 75:25로 혼합하여 $520^{\circ}C$에서 소성한 경우 밀도 및 수축율의 변화를 거의 나타나지 않았다. 그러나 $TiO_2$함량이 15wt.%를 혼합하여 첨가했을 경우 반사율은 높고 접합특성 또한 우수하였다. 또한, 유전상수는 $TiO_2$첨가량이 증가함에 따라 증가하는 경향을 나타내었다.