http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
산화티탄의 광전기화학 특성을 이용한 퍼클로레이트 이온 제거
민형섭,이전국,Min, Hyung-Seob,Lee, Jeon-Kook 한국재료학회 2008 한국재료학회지 Vol.18 No.8
Titanium oxide films and powders are attached onto carbon cloths via RF reactive sputtering and an epoxy resin mixture, respectively. $TiO_2$/carbon composite materials were used to investigate the photoelectrochemical degradation of perchlorate ions in water. The energy band gaps of the RF-sputtered $TiO_2$ thin films ranged from 3.35-3.44 eV. A photocurrent of the powdered $TiO_2$ as illuminated by ultra-violet light for 30 min. was $2.79\;mA/cm^2$. Perchlorate ions in water were shown to be degradable by a UV-illuminated $TiO_2$ powder/carbon/Nafion/carbon composite.
탄소 전극 형상 변화에 따른 전기화학 커패시터 특성 향상
민형섭,김상식,정덕수,최원국,오영제,이전국,Min, Hyung-Seob,Kim, Sang-Sig,Cheong, Deock-Soo,Choi, Won-Kook,Oh, Young-Jei,Lee, Jeon-Kook 한국재료학회 2009 한국재료학회지 Vol.19 No.10
Activated carbon (AC) with very large surface area has high capacitance per weight. However, such activation methods tend to suffer from low yields, below 50%, and are low in electrode density and capacitance per volume. Carbon NanoFibers (CNFs) had high surface area polarizability, high electrical conductivity and chemical stability, as well as extremely high mechanical strength and modulus, which make them an important material for electrochemical capacitors. The electrochemical properties of immobilized CNF electrodes were studied for use as in electrical double layer capacitor (EDLC) applications. Immobilized CNFs on Ni foam grown by thermal chemical vapor deposition (CVD) were successfully fabricated. CNFs had a uniform diameter range from 50 to 60 nm. Surface area was 56 m$^2$/g. CNF electrodes were compared with AC and multi wall carbon nanotube (MWNT) electrodes. The electrochemical performance of the various electrodes was examined with aqueous electrolyte of 2M KOH. Equivalent series resistance (ESR) of the CNF electrodes was lower than that of AC and MWNT electrodes. The specific capacitance of 47.5 F/g of the CNF electrodes was achieved with discharge current density of 1 mA/cm$^2$.
강유전체를 이용한 MeFINS 구조 캐퍼시터의 비휘발성 소자 특성
박노헌,민형섭,김지영 국민대학교 생산기술연구소 2002 공학기술논문집 Vol.25 No.-
In this study, ferroelectric thin films such as SBT (SrBi₂Ti₂O_(5)) are directly employed as a gate dielectric for nonvolatile memory applications. ICP nitride and Ta₂O_(5) layers were used in order to avoid interdiffusion between ferroelectric and Si and formation of low dielectric constant layer due to oxidation of Si, respectively. MeFINS (Pt/SBT/Ta₂O_(5)/SiN_(x)/Si) capacitors with ICP nitrogen treatments show higher total capacitance than MeFIS capacitors without treatment. This implies that ICP nitridation successfully suppresses undesirable oxide formation even under extremely severe SBT annealing conditions and results in high actual applying voltage on ferroelectrics layer. As a result, the MeFINS capacitors with ICP treatments exhibits wider memory window (△V =1.36V) than that of MeFIS (△V =0.6V) device under ?V sweeping voltage operation.
폴리머 기판위에 형성된 나노구조제어 알루미나의 캐패시터 특성
정승원,민형섭,한정환,이전국,Jung, Seung-Won,Min, Hyung-Sub,Han, Jeong-Whan,Lee, Jeon-Kook 한국재료학회 2007 한국재료학회지 Vol.17 No.2
Embedded capacitor technology can improve electrical perfomance and reduce assembly cost compared with traditional discrete capacitor technology. To improve the capacitance density of the $Al_2O_3$ based embedded capacitor on Cu cladded fiber reinforced plastics (FR-4), the specific surface area of the $Al_2O_3$ thin films was enlarged and their surface morphologies were controlled by anodization process parameters. From I-V characteristics, it was found that breakdown voltage and leakage current were 23 V and $1{\times}10^{-6}A/cm^2$ at 3.3 V, respectively. We have also measured C-V characteristics of $Pt/Al_2O_3/Al/Ti$ structure on CU/FR4. The capacitance density was $300nF/cm^2$ and the dielectric loss was 0.04. This nano-porous $Al_2O_3$ is a good material candidate for the embedded capacitor application for electronic products.
고체 윤활 층의 미세구조 변화에 따른 우주발사체 엔진 터보펌프용 극저온 베어링 회전특성 변화에 관한 연구
김초희,서우석,민형섭,최복성,류솔지,이병국,이용복,이전국,최용 한국항공우주학회 2014 한국항공우주학회 학술발표회 논문집 Vol.2014 No.11
모재 SUS440C에 고체 윤활을 코팅하였다. 은 재료의 밀도를 변화시키기 위하여, 전기도금 용액의 이온 농도를 30~90g/ℓ까지 변화시켰다. 극저온에서의 액체 질소 상태에서는, 11000rpm의 고속회전 특성이 은 재료의 밀도 변화에 따라 관찰되었다. 또한, 회전 실험 후에, 은코팅된 표면의 미세구조 변화와 물질의 이동 현상을 광학 현미경을 통해 살펴보았다. 그 후, 상호적인 관계를 분석하였다. The basic material of SUS440C was coated with a solid lubricant. To change the density of silver material, the ion concentration of the electroplating solution was changed for 30 ~ 90g /ℓ . when it was liquid nitrogen condition at very low temperature, the characteristic of high speed rotation of 11000 rpm speed was observed according to density changes of silver material. also, after rotation experiment, the changes of fine structure of silver-plated surface and the phenomena of material moving was observed through Optical Microscope, and its mutual relation was analyzed.
PZT 박막 캐퍼시터의 특성에 기여하는 PZT-전극계면층의 영향
김태호,구준모,민형섭,이인섭,김지영,Kim, Tae-Ho,Gu, Jun-Mo,Min, Hyeong-Seop,Lee, In-Seop,Lee, In-Seop 한국재료학회 2000 한국재료학회지 Vol.10 No.10
Metal-Ferroelectric-Metal(MFM) 구조의 개퍼시터에서 $Pb(Zr,Ti)O_3(PZT)$-전극 계면층이 PZT 박막 특성에 기여하는 영향을 알아보기 위하여 Pt/PZT/계면층/Pt/$TiO_2/SiO_2$/Si 구조의 캐퍼시터를 제작하였다. 계면층으로 사용될 물질들 중에서 $PbTiO_3(PT)$ 층을 sol-gel 방법으로 형성하였으며, PbO, $ZrO_2,\;TiO_2$ 층들을 reactive sputtering 방법으로 형성하였다. PZT박막을 구성하는 원소들로 이루어진 단순 산화물들의 특성을 평가하기 위하여 PbO, $ZrO_2,\;TiO_2$를 계면층으로 사용하여 $600^{\circ}C$에서 열처리를 실시하였고, 이 경우에는 $TiO_2$가 가장 우수하게 PZT의 결정립 크기를 미세하게 하는 효과를 보였으나, 두께가 증가함에 따라 표면 거칠기가 증가하고 anatase 상으로 남기 때문에 강유전특성이 열화되었다. 반면에 PT 박막을 계면층으로 사용한 경우에는 결정립 크기의 감소와 더불어 전기적인 특성도 향상되었다. 또한 PZT의 핵생성 위치를 판단하기 위하여 PT 삽입층의 위치를 변화하며, 실험한 결과, 하부전극과 PZT 박막의 계면에 PT 삽입층을 형성하였을 경우에 가장 효과적인 seed로서의 역할을 하였다. In order to study effects of interfacial layers between $Pb(Zr,Til)Q_3(PZT)$ films and electrodes for Metal-Ferroelectric-MetaI(MFM) structure capacitors, we have fabricated the capacitors with the Pt/PZT/interfacial-layer/Pt/$TiO_2/SiO_2$/Si structure. $PbTiO_3(PT)$ interfacial layers were formed by sol-gel deposition and PbO, ZrO, and $TiO_2$ thin layers were deposited by reactive sputtering. $TiO_2$ interface layers result in the finest grains of PZT(crystalline Temp. $600^{\circ}C$) films compare to $PbO_2\;and\;ZrO_2$ layers. However, as the thickness of $TiO_2$ layer increases. PZT thin films become rough and electrical characteristics were deteriorated due to remained anatase phase. On the other hand. PT interface layers result in improved morphology of PZT films and do not significantly change ferroelectric properties. It is a also observed that seed layers at the middle and top of PZT films do not give significant effects on grain size but the PT seed layer at the interface between the bottom electrode and the PZT films results in the small grain size.
침상구조의 루틸상 TiO<sub>2</sub> 초미분체를 이용한 광촉매 반응에 대한 연구
황두선,구숙경,김광수,민형섭,이은구,김선재,Hwang, Doo-Sun,Ku, Suk-Kyeong,Kim, Kwang-Su,Min, Hyung-Seob,Lee, Eun-Gu,Kim, Sun-Jae 한국재료학회 2002 한국재료학회지 Vol.12 No.8
The redox properties of a homogeneously-precipitated $TiO_2$ rutile powder with a BET surface area of ~$200 m^2$/g, consisting of an acicular primary particle, were characterized using photocatalytic reaction in aqueous 4-chlorophenol, Cu-EDTA and Pb-EDTA solutions under ultraviolet irradiation, compared to those of commercial P-25 X$200 m_2$ powder with a spherical primary particle as well as home-made anatase $TiO_2$ powder with ~$200 m^2$/g BET surface area. Here, the anatase powder also includes mainly the primary particles very similar to the acicular shapes of the rutile $TiO_2$ powder. The rutile powder showed the fastest decomposition rate and the largest amount in the photoredor, compared with the anatase or P-25 powder, while the anatase powder unexpectedly showed the slowest rate and the smallest amount in the same experiments regardless of almost the same surface area. From results, the excellent photoredox abilities of this rutile powder appears to be due to specific powder preparation method, like a homogeneous precipitation leading to direct crystallization from the solution, regardless of their crystalline structures even when having the similar particle shape and surface area.