• Journal of Magnetics
• /
• 제16권2호
• /
• pp.161-163
• /
• 2011

We report results of first principles calculations for effects of an external electric field (E-field) on the magnetocrystalline anisotropy (MCA) in transition-metal (Fe, Co, and Ni) monolayers and at metal-insulator (Fe/MgO) interfaces by means of full-potential linearized augmented plane wave method. For the monolayers, the MCA in the Fe monolayer (but not in the Co and Ni) is modified by the E-field, and a giant modification is achieved in the $Fe_{0.75}Co_{0.25}$. For the Fe/MgO interfaces, the ideal Fe/MgO interface gives rise to a large out-of plane MCA, and a MCA modification is induced when an E-field is introduced. However, the existence of an interfacial FeO layer between the Fe layer and the MgO substrate may play a key role in demonstrating an Efield-driven MCA switching, i.e., from out-of-plane MCA to in-plane MCA.

• 대한전자공학회논문지SD
• /
• 제38권6호
• /
• pp.390-397
• /
• 2001

GIDL(Gate-Induced Drain-Leakage)을 줄일 수 있는 새로운 구조의 ESD(Elevated Source Drain) MOSFET을 제안하고 분석하였다. 제안된 구조는 SDE(Source Drain Extension) 영역이 들려진 형태를 갖고 있어서 SDE 임플란트시 매우 낮은 에너지 이온주입으로 인한 저활성화(low-activation) 효과를 방지 할 수 있다. 제안된 구조는 건식 식각 및 LAT(Large-Angle-Tilted) 이온주입 방법을 사용하여 소오스/드레인 구조를 결정한다. 기존의 LDD MOSFET과의 비교 시뮬레이션 결과, 제안된 ESD MOSFET은 전류 구동능력은 가장 크면서 GIDL 및 DIBL(Drain Induced Barrier Lowering) 값은 효과적으로 감소시킬 수 있음을 확인하였다. GIDL 전류가 감소되는 원인으로는 최대 전계의 위치가 드레인 쪽으로 이동함에 따라 최대 밴드간 터널링이 일어나는 곳에서의 최대 전계값이 감소되기 때문이다.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2002년도 춘계학술대회 논문집
• /
• pp.451-456
• /
• 2002

This paper describes the properties of Temperature-Viscosity characteristics of hydrous and anhydrous ER fluids containing starch and titanium particle in silicone oil. ER effects arise from electrostatic forces between the starch particles and titanium particles dispersed in the electrically insulating silicone oil induced when electric field is applied. ER fluids under electric field have been found to provide resonable estimates of ER fluid viscosity variation characteristics. Yield shear stress of the ER fluids were measured on the couette cell type rheometer as a function of electric fields. The outer cup is connected to positive electrode(+) and bob becomes ground(-). The electric field is applied by high voltage DC power supply. In this experiment shear rates were increased from 0 to 200/equation omitted/ in 2 minutes.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2007년도 춘계학술대회논문집
• /
• pp.943-946
• /
• 2007

In-plane piezoelectric charge constant of Electro-Active paper (EAPap) was investigated based on direct and converse piezoelectric effects. EAPap samples were made with cellulose film with very thin gold electrode coated on both sides of the film. To characterize direct piezoelectricity of EAPap, induced charge was measured when mechanical stress was applied to EAPap. In-plane piezoelectric charge constant was extracted from the relation between induced charge and applied in-plane normal stress. To investigate converse piezoelectricity, induced in-plane strain was measured when electric field was applied to EAPap. Piezoelectric charge constant was also extracted from the relation of induced in-plane strain and applied electric field. Piezoelectric charge constants obtained from direct and converse piezoelectricity are 31 pC/N and 178 x 10-12m/V for 45 degree sample, respectively. Measured piezoelectric charge constants of EAPap provide promising potential as a piezoelectric material.

• 대한전기학회논문지
• /
• 제43권6호
• /
• pp.1001-1009
• /
• 1994

The present paper deals with a new developed sensor for measuring the time-varying magnetic fields and describes the experimental results of trasient magnetic field that takes place during the operations of electric appliance. The operation principle of the self-integrating magnetic field sensor by using coaxial cable is analyzed and a calibration investigation is carried out. The frequency bandwidth of the magnetic field measurement system is from 40 Hz to about 300 kHz. The magnetic field induced by the starting and/or operation of electric appliance mainly includes the odd harmonics such as the third, the fifth and the seventh harmonics. The magnetic field intensity caused during the operation of ultrasonic washer is inversely proportional to distance, this correspodns to induction component. As a result, it was known that the odd harmonics of magnetic field in the desing of electromagnetic shield employed for protecting electronic circuit and control devices have to be considered.

• 한국재료학회지
• /
• 제9권1호
• /
• pp.81-85
• /
• 1999

Polarization and strain induced by unipolar electric field (P\ulcorner, S\ulcorner), those induced by bipolar electric field (P, S) and remanent polarization (P\ulcorner) were investigated in 0.9Pb(Mg\ulcornerNb\ulcorner)O$_3$-$0.1PbTiO_3$relaxor ferroelectric ceramics in the temperature range of $-50^{\circ}C$~$90^{\circ}C$. From the temperature dependence of polarization and strain, the transition from predominantly paraelectric (electrostrictive) to partially ferroelectric (piezoelectric) is visualized. Under the given temperature, the P\ulcorner/P\ulcorner is always larger than the S\ulcorner/S\ulcorner and the difference between them becomes larger ass the temperature decrease. The S\ulcorner/P\ulcorner increases as the temperature decreased below phase transition temperature. It was suggested that these experimental results might be explained with a simple rigid ion model concentrating on BO\ulcorner octahedron.

• E2M - 전기 전자와 첨단 소재
• /
• 제10권9호
• /
• pp.909-915
• /
• 1997

To improve the electro-induced strain and to decease the hysteresis of that W $O_3$dopant of which amount is 0~0.8wt% was added to (P $b_{0.73}$/B $a_{0.27}$)(Z $r_{0.75}$/ $Ti_{0.25}$) $O_3$+0.1wt% $Y_{2}$/ $O_3$ceramics. At the specimen with 0.4 wt% W $O_3$the electromechanical coupling coefficient( $K_{31}$ ) showed the maximum value of 23.6% at D.C 10 kV/cm electric field. At the same W $O_3$addition amount the piezoelectric constant( $d_{31}$ ) and the electro-induced strain($\Delta$$\ell$/$\ell$)showed the highest values of 182$\times$10$^{-12}$ [C/N] 210$\times$10$^{-6}$ $\Delta$$\ell$/$\ell$at D.C. 10 kV/cm electric field. respectively0 kV/cm electric field. respectivelyvely.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
• /
• pp.375-378
• /
• 2002

There has recently been a great deal of interest in amorphous selenium for application of digital x-ray image sensor. The initial number of the electron-hole induced by interaction a-Se with x-ray photons and the collection efficiency to surface of generated charges are important parameters for x-ray sensitivity of the a-Se. Therefore, in this paper, we analyzed that thickness of a-Se film and electric field is affected on the initial number of electron-hole and the collection efficiency. The experimental value of x-ray induced charge about the various thickness and the electric field is compared with estimated absorbed energy through MCNP 4C code to analyze the mechanism x-ray induced signal of a-Se. The experimental results showed that the electric field depends on initial escape coefficient and the thickness depends on collection coefficient than escape efficient.

• 한국전기전자재료학회논문지
• /
• 제34권5호
• /
• pp.271-282
• /
• 2021

The internet of things (IoT) technology is a key component for the advent of 4^th industrial revolution, which is the network of home appliances, infrastructures, and vehicles to remotely investigate these systems. For the operation of compact IoT devices, batteries are widely used as electric power, and the limited lifetime of batteries inevitably leads to periodic replacement. Magneto-mechano-electric (MME) generators may be alternatives to batteries inside the IoT devices by converting stray magnetic field into electric energy, since we are always surrounded by ambient alternating current (AC) magnetic fields induced from electric power transmission lines everywhere. This article reviews the recent domestic research progress in high-performance MME generators and their application field for IoT and electronic devices.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제9권6호
• /
• pp.500-505
• /
• 2004

The present study was to investigate the purification of a fermentation broth by an electromicrofiltration membrane. Microfiltration runs with a crude and a centrifuged broth, with solution of particles recovered from centrifugation and with permeates from microfiltration experiments were thus compared. Microfiltration performances were governed by colloids and small particles that induced sharp initial flux declines. For these results, the evolution of the overall membrane resistance was increased by $80\%$ in comparison with the electromicrofiltration membrane. The main focus of this study was set on the enhancement of the filtrate flux by an electric field. This pressure electrofiltration leads to a drastic improvement of the filtration by $100\%$ and the filtration time was thereby reduced. Pressure electrofiltration serves as an inter­esting alternative to the cross-flow filtration and it effectively separates advantageous constitu­ents such as amino acids and biopolymers from a fermentation broth. They were equally main­tained during the microelectrofiltration, although they were significantly reduced by $45\%$ by the microfiltration without the application of an electric field. Accordingly, since the electrofiltration membrane was provided more permeability, this study experimentally demonstrates that the permeability inside a membrane can be controlled using an electric field.