• JSTS:Journal of Semiconductor Technology and Science
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• 제16권1호
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• pp.106-111
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• 2016

Thermal noise generated in the electrolyte is modeled for the electrolyte-oxide-semiconductor field-effect transistors. Two noise sources contribute to output noise currents. One is the thermal noise generated in the bulk electrolyte region, and the other is the thermal noise from the double-layer region at the electrolyte-oxide interface. By employing two slightly-different equivalent circuits for two noise current sources, the power spectral density of output noise current is calculated. From the modeling and simulated results, the bulk electrolyte thermal noise dominates the double-layer thermal noise. Electrolyte thermal noise are computed for three different concentrations of NaCl electrolyte. The derived formulas give a good agreement with the published experimental data.

• ETRI Journal
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• 제13권2호
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• pp.21-27
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• 1991

Effects of annealing on the dielectric properties and microstructures of thin tantalum oxide film(25nm) deposited on p-type Si substrate with rf reactive magnetron sputtering were investigated. The leakage current density was remarkably reduced from $10^-8$ to $10^-12$ A/$\mum^2$at the electric field of 2MV/cm after rapid thermal annealing(RTA) in $O_2$at $1000^{\circ}C$, while little leakage reduction was observed after furnace annealing in $O_2$ at $500^{\circ}C$. The structural changes of thin tantalum oxide film after annealing were examined using high resolution electron microscope(HREM). The results of HREM show that substantial reduction in the leakage current density after the RTA in $O_2$ can be attributed to crystallization and reoxidation of the thin amorphous tantalum oxide film.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.198-199
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• 2006

$SrTa_2O_6$(STA) thin films were fabricated by sol-gel method. The films annealed below $700^{\circ}C$, showed amorphous phase and crystallization phase was observed after annealing over $800^{\circ}C$. From high frequency capacitance-voltage measurements, 24nm thick STA thin film annealed at $900^{\circ}C$, has an EOT of 5.7nm and a dielectric constant of 16. Leakage current characteristics were improved by the insertion of chemical oxide between STA and Si. Leakage current densities are around $3.5{\times}10^{-7}A/cm^2$ at 5V for the structure inserted chemical oxide but $1.4{\times}10^{-6}A/cm^2$ at 5V without chemical oxide.

• 방사성폐기물학회지
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• 제20권4호
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• pp.383-398
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• 2022

The electrochemical behavior was investigated during the electrolysis of nickel oxide in LiCl-Li₂O salt mixture at 650℃ by changing several components. The focus of this work is to improve anode design and shroud design to increase current densities. The tested components were ceramic anode shroud porosity, porosity size, anode geometry, anode material, and metallic porous anode shroud. The goal of these experiments was to optimize and improve the reduction process. The highest contributors to higher current densities were anode shroud porosity and anode geometry.

• 전기화학회지
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• 제12권1호
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• pp.1-10
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• 2009

This article reviewed transport behaviours of electroactive species in ionic compounds, focusing on chemical diffusion of Li through the transition metal oxide in a current flowing condition. For this purpose, a distinction has been first briefly made between migration and diffusion with respect to current, driving force and charge of electroactive species considered. Then, the equations for chemical diffusion are derived theoretically in open-circuit and current flowing conditions. Finally, the experimental methods such as ac impedance spectroscopy and current (potential) transient techniques are described in details for characterising chemical diffusion. In addition, the role of the thermodynamic enhancement factor in chemical diffusion is discussed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2222-2227
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• 2007

Newly structured metal-supported solid oxide fuel cell was fabricated and characterized by impedance analysis and galvanodynamic experiment. Using a cermet adhesive, thin ceramic layer composed of anode(Ni/YSZ) and electrolyte(YSZ) was joined with STS430 metal support of which flow channel was fabricated. $La_{0.8}Sr_{0.2}Co_{0.4}Mn_{0.6}O_3$ perovskite oxide was used as cathode material. Single cell performance was increased and saturated at operating time to 300hours at 800$^{\circ}C$ because of cathode sintering effect. The sintering effect was reinvestigated by half cell test and exchange current density was measured as 0.005A/$cm^2$. Maximum power density of the cell was 0.09W/$cm^2$ at 800$^{\circ}C$. Numerical analysis was carried out to classify main factors influencing the single cell performances. Compared to experimental IV curve, simulated curve based on experimental parameters such as exchange current density was in good agreement.

• Transactions on Electrical and Electronic Materials
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• 제16권6호
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• pp.308-311
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• 2015

V₂O₅/Mn₃O₄/Nb₂O₅ codoped zinc oxide varistor ceramics were sintered at a temperature range as low as 875~950℃. The voltage clamping characteristics of V₂O₅/Mn₃O₄/Nb₂O₅ codoped zinc oxide varistor ceramics were investigated at a pulse current range of 1~50 A. The sintering temperature had a significant effect on clamp voltage ratio, which exhibits surge protection capabilities. The varistor ceramics sintered at 875℃ exhibited the best clamping characteristics, in which the clamp voltage ratio was 2.69 at a pulse current of 50 A. The varistor ceramics sintered at 900℃ exhibited the highest electrical stability, where = 3,824 V/cm (initial 3,909 V/cm), and E_{1 mA/cm²} = 27 (initial 39) after application of a pulse current of 100 A.

• 한국세라믹학회지
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• 제49권6호
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• pp.498-504
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• 2012

Oxide layers were prepared by an environmentally friendly plasma electrolytic oxidation (PEO) process on an Al-1050 substrate. The electrolyte for PEO was an alkali-based solution with $Na_2SiO_3$ (8 g/L) and NaOH (3 g/L). The influence of the electrical parameters on the phase composition, microstructure and properties of the oxide layers formed by PEO were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The voltage-time responses were recorded during various PEO processes. The oxides are composed of two layers and are mainly made of ${\alpha}$-alumina, ${\gamma}$-alumina and mullite phases. The proportion of each phase depends on various electrical parameters. It was found that the surface of the oxides produced at a higher current density and Ia/Ic ratio shows a more homogeneous morphology than those produced with the electrical parameters of a lower current density and lower Ia/Ic ratio. Also, the oxide layers formed at a higher current density and higher Ia/Ic ratio show high micro-hardness levels.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.411.1-411.1
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• 2016

In this study, we examined the effects of boron doping on the dielectric reliability of solution processed aluminum oxide ($Al_2O_3$). When boron is doped in aluminum oxide, the hysteresis reliability is improved from 0.5 to 0.4 V in comparison with the undoped aluminum oxide. And the accumulation capacitance is increased when boron was doped, which implying the reduction of the thickness of dielectric film. The improved dielectric reliability of boron-doped aluminum oxide is originated from the small ionic radius of boron ion and the stronger bonding strength between boron and oxygen ions than that of between aluminum and oxygen ions. Strong boron-oxygen ion bonding in aluminum oxide results dielectric film denser and thinner. The leakage current of aluminum oxide also reduced when boron was doped in aluminum oxide.

• Journal of Electrochemical Science and Technology
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• 제9권2호
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• pp.93-98
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• 2018

$MnO_2$, a metal oxide used as an electrode material in electrochemical capacitors (EDLCs), has been applied in binary oxide and conducting polymer hybrid electrodes to increase their stability and capacitance. We developed a method for electrodepositing Mn-Ni oxide/PANI, Mn-Ni oxide/PEDOT, and Mn-Ni-Ru oxide/PEDOT films on carbon paper in a single step using a mixed bath. Mn-Ni oxide/PEDOT and Mn-Ni-Ru oxide/PEDOT electrodes used in an electro-osmotic pump (EOP) have shown better efficiency compared to Mn-Ni oxide and Mn-Ni oxide/PANI electrodes through testing in water as a pumping solution. EOP using a Mn-Ni-Ru oxide/PEDOT electrode was also tested in a 0.5 mM $Li_2SO_4$ solution as a pumping solution to confirm the effect of the $Li^+$ insertion/de-insertion reaction of Ruthenium oxide on the EOP. Experimental results show that the flow rate increases with the increase in current in a 0.5 mM $Li_2SO_4$ solution compared to that obtained when water was used as a pumping solution.