• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.362-365
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• 2002

Hf thin films were deposited on bottom metal using a RF magnetron sputtering method followed by oxidation and annealing in O$_2$ and N$_2$ ambient, respectively. Various top metal electrodes (i.e., Al, Au, and Cu) were deposited by evaporation, and their roles on physical and electrical properties were investigated. Using the XRD, SEM and AFM techniques, we confirmed that the grain size of HfO$_2$ thin films enlarges as a function of oxidation temperature, increasing dielectric constant. However, other electrical properties (e.g., tan) deteriorateas a consequence. The dielectric constant and tan of HfO$_2$ thin films oxidized at 500 $^{\circ}C$ were 17-25 and 3${\times}$10-3 - 2x10-2, respectively, in the frequency range of 1 Hz to 1 MHz. The leakage current density was less than 1${\times}$10-8A/cm2 up to 0.7 MV/cm. In addition, electrical properties of HfO$_2$ thin films (e.g., the dielectric constant, leakage current and tan $\delta$) depend on top metal electrode. We showed that Al top metal electrode results in the best result.

• 센서학회지
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• 제14권6호
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• pp.423-429
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• 2005

In this paper, we proposed the fabrication process of the stable e-beam evaporation and the patterning of metals layer on the polydimethylsiloxane (PDMS) substrate. The metal layer was deposited under the various deposition rate, and its effect to the electrical and mechanical properties (e.g.: adhesion-strength of metal layer) was investigated. The influence of surface roughness to the adhesion-strength was also examined via the tape test. Here, we varied the roughness by changing the reactive ion etching (RIE) duration. The electrode patterning was performed through the conventional photolithography and chemical etching process after e-beam deposition of $200{\AA}$ Ti and $1000{\AA}$ Au. As a result, the adhesion strength of metal layer on the PDMS surface was greatly improved by the oxygen plasma treatment. The e-beam evaporation on the PDMS surface is known to create the wavy topography. Here, we found that such wavy patterns do not effect to the electrical and mechanical properties. In conclusion, the metal patterns with minimum $20{\mu}m$ line width was produced well via the our fabrication process, and its electrical conductance was almost similar to the that of metal patterns on the silicon or glass substrates.

• 공업화학
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• 제5권1호
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• pp.81-89
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• 1994

고성능 니켈/금속수소 축전지를 개발하기 위하여 전극용량도 비교적 높고, 합금가격이 저렴한 Mm계 전극에 대하여 P-C-T 특성, 충방전 특성, microencapsulation 방법 및 그 효과 등에 관한 연구를 수행하였다. P-C-T 특성조사로부터 플라토압력, 수소저장량을 구하였는데, Mm계 합금인 경우는 각각 0.4기압, 310mAh/g으로 나타났다. Microencapsulation 처리를 함으로써 도전재를 혼합한 전극보다 전극용량 및 전극의 안정성을 향상시켰으며, 또한 전처리없이 microencapsulation처리가 가능하였다. Microencapsulation 처리한 Mm계 합금의 전극용량은 240~250 mAh/(0.2 C)이었다.

• 품질경영학회지
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• 제21권2호
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• pp.242-253
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• 1993

The interpretation of the reaction mechanism is significant to produce the high quality welds and understand the welding processes. This investigation is important for the design of welding consumables and the selection of welding process parameters to develop the high quality welds. The objective of this study is to investigate the effect of electrochemical reactions on the transfer of alloy elements between slag and weld metal during submerged arc welding During submerged arc welding weld metal composition is shown to be controlled by two reaction mechanisms in four reaction zones. The responsible reaction mechanisms are thermochemical and electrochemical reactions. The possible reaction sites are the melted electrode tip, the detached droplet, the hot weld pool immediately below the moving electrode, and the cooling and solidifying weld pool behind the moving electrode. The possible reactions in submerged arc welding at different zones of the process is schematically shown in Figure 1.

• 한국해양공학회지
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• 제17권4호
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• pp.52-58
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• 2003

Underwater wet arc welds were experimentally performed on the KR-RA steel plate as base metal by using four different types of flux coated electrodes: KT33, UWEE, UWCS, and TN20, UWEE, the individually designed flux coated underwater electrode, had good operability when compared with other domestic terrestrial electrodes, and imported goods. The hardness value and the portion of martensite of HAZ were increased, by using a rapid cooling rate, Mechanical properties were also examined experimentally with a multi-pass butt-welding specimen test. The individually designed flux coated electrode UWEE could be used in practice for underwater wet welds.

• 산업기술연구
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• 제24권A호
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• pp.9-15
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• 2004

The flexural strength from 3-point bend test and fatigue properties were measured to evaluate mechanical properties of metal/ceramic interface of the multilayer ceramic package produced through tape casting. From the results, the specimens with three electrode layers showed the highest strength. The temperature distribution with time during thermal cycle and thermal stresses with the change of electrode's shape have been estimated by mathematical modelling. Specimen affected by thermal shock, produced microcracks by the difference of thermal expansion coefficient. The results of tensile test and fatigue test showed the rupture at pin. The fact that the pin brazed specimens were always fractured at the pin proved the good bonding condition between pin and electrode.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• 제6권1호
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• pp.75-81
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• 2003

Underwater wet arc welds were experimentally performed on the KR-RA steel plate as base metal by using four different types of flux coated electrodes: KT33, UWEE, UWCS, and TN20. UWEE, the individually designed flux coated underwater electrode, had good operability when compared with other domestic terrestrial electrodes, and imported goods. The hardness value and the portion of martensite of HAZ were increased, by using a rapid cooling rate, Mechanical properties were also examined experimentally with a multi-pass butt-welding specimen test. The individually designed flux coated electrode UWEE could be used in practice for underwater wet welds.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2277-2280
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• 2014

The contact properties between gold and poly(3-hexylthiophene) (P3HT) films having either of two distinct molecular orientations and orderings were investigated. Thermal treatment increased the molecular ordering of P3HT and remarkably reduced the contact resistance at the electrode/semiconductor interface, which enhanced the electrical performance. This phenomenon was understood in terms of a small degree of metal penetration into the P3HT film as a result of the thermal treatment, which formed a sharp interface at the contact interface between the gold electrode and the organic semiconductor.

• Toxicological Research
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• 제33권2호
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• pp.135-140
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• 2017

The cobalt (Co(II)) ion is a main component of alloys and considered to be carcinogenic, especially due to the carcinogenic and toxicological effects in the aquatic environment. The toxic trace of the Co(II) detection was conducted using the infrared photodiode electrode (IPDE) using a working electrode, via the cyclic and square-wave anodic stripping voltammetry. The results indicated a sensitive oxidation peak current of Co(II) on the IPDE. Under the optimal conditions, the common-type glassy carbon, the metal platinum, the carbon paste, and the carbon fiber microelectrode were compared with the IPDE in the electrolyte using the standard Co(II). The IPDE was found to be far superior to the others.

• 정보저장시스템학회논문집
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• 제9권1호
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• pp.22-27
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• 2013

In this paper we are presenting a architecture of Co ion decorated graphene oxide as an electrode for supercapacitor application. Graphene oxide, which is exfoliated by oxidant from graphite, is the material for solving the problem of mass production and coating on the surface of working electrode. The $Co^{2+}$ ions are coated by using layer by layer(LBL) method on graphene oxide foam. The metal ion decorated graphene oxide shows enhanced capacitance performance when tested as supercapacitor electrode, showing the specific capacitance of $827Fg^{-1}$.