• Electrical & Electronic Materials
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• v.9 no.6
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• pp.551-557
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• 1996

To decrease the hysteresis of electric field induced strain, $Y_{2}$ $O_{3}$ dopant of which amount is 0-0.8wt% was added to the (P $b_{0.73}$B $a_{0.27}$)(Z $r_{0}$ 75/ $Ti_{0.25}$) $O_{3}$ ceramics. Electromechanical coupling coefficients of the specimen with 0.1 Wt% $Y_{2}$ $O_{3}$ were $k_{p}$=26.9% and $k_{31}$ =20.4%, which exhibited the maximum value at the constant bias electric field of 10 kV/cm. At the same $Y_{2}$ $O_{3}$ addition amount, electric field piezoelectric constant ( $d_{3l}$) and strain(.DELTA.l/l) showed the maximum values of 139.6*10$^{-12}$ [C/N] and 126*10$^{-6}$ .DELTA. l/l respectively at 10 kV/cm electric field. And the hysteresis of strain showed the minimum value of 17.5%. So, we propose that it is possible to apply PBZT system with $Y_{2}$ $O_{3}$ dopant to the electrostrictive actuator.r.r.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1143-1146
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• 2003

This paper was simulated the electric field distribution in dielectric tube with two layers and spherical dielectric in water. The reactor was made up of the spherical dielectric that is diameter : 2.5[mm], ${\epsilon}_r$ : 5, 25, 100, 1000, 5000 respectively and two glass plate being 2[mm] thickness, ${\epsilon}_r$ : 5 as electrode. The discharge gap was 9[mm]. As a result of the simulation, in case of being about the same value between the dielectric constant of spherical dielectric and water, when the reactor was applied to high voltage, dielectric polarization characteristic was trending toward disappearance. To get more strong electric field, the dielectric constant should be higher comparatively, Increasing the spherical dielectric constant, the location of equippotential line was shifting from the interior to the exterior.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.44-47
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• 2003

In this paper, the electric field distribution in dielectric tube with one layer and spherical dielectric($ZrO_2$) in water was simulated. The reactor was made up of the spherical dielectric that is diameter : 3.0[mm], $ZrO_2(\varepsilon_r:10)$ and one glass plate of thickness(2[mm]), $\varepsilon_r$(10) as electrode. The discharge gap was 8[mm]. To get more strong electric field, the dielectric constant should be higher comparatively. Using the spherical dielectric for water discharge in dielectric tube, the location of equipotential line was shifting from the interior to the exterior. At real water discharge experimental, ozone was measured higher dissolved ozone in water at condition of water rate(l[l/min]) and injector than condition of non-injector or 2~3[l/min].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.40-43
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• 2003

In this paper, the electric field distribution in dielectric tube with one layer and spherical dielectric(glass) in water was simulated. The reactor was made up of the spherical dielectric that is diameter : 3.0[mm], glass(${\varepsilon}_r$:5) and one glass plate of thickness(2[mm]), ${\varepsilon}_r$(5) as electrode. The discharge gap was 8[mm). Toget more strong electric field, the dielectric constant should be higher comparatively. Using the spherical dielectric for water discharge in dielectric tube, the location of equipotential line was shifting from the interior to the exterior. At real water discharge experimental, $H_2O_2$ was measured higher generated $H_2O_2$ in water at condition of water rate(1[l/min]) and injector than condition of non-injector or 2-3[l/min])

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.427-428
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• 2009

The authors investigated anomalous nanoporous structures of aluminum oxides during the Al anodization process. We implemented two-steps anodizing process for the electrolyte of oxalic acid. As increasing DC voltages, lattice constants are proportionally increased. For the curved surface, the surface electric field was distorted so that the nanoporous pipe channel changed to a cone-type shape. We confirmed the periodicity by using the FFT(Fast Fourier Transform) analysis.

• Korean Journal of Materials Research
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• v.8 no.3
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• pp.252-255
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• 1998

In this paper, we investigate the magneto-impedance(M1) effect of the FeCoSiB amorphous magnktic films. The amorphous magnetic film having near zero magnetostriction is fabricated by using the sputtering method, and then annealed in magnetic field. When the external magnetic field is directly applied to the fabricated film, the voltage amplitude between both side of the magnetic film varies about 76.2% at 120[MHzl and the impedance varies about 2.1%/0e. Thus, we find that the fabricated magnetic film has the characteristics of good sensor element.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.3
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• pp.81-85
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• 2003

This paper describes the results of experiments made to examine the behavior of water droplet on the polymer surface and influence of the charge. In this experiment, water droplet was put on the polymer surface in an applied AC electric field and the investigations of its behavior were done with a high-speed video camera. It can be observed that the droplet elongates and vibrates with being pulled towards the positive electrode in a wave synchronism with the frequency of the power source. The volume and conductivity of water droplet are shown to have a marked effect on the mode of discharge development. These behaviors may be caused by the change of electric field of applied AC voltage and induced charges in/on the water droplet.

• Journal of the Korean Ceramic Society
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• v.47 no.6
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• pp.623-626
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• 2010

We synthesized ZnO nanowires patterned on Si substrate and investigated the field emission properties of the nanowires. Firstly, Au catalyst layers were fabricated on Si substrate by photo-lithography and lift-off process. The diameter of Au pattern was $50\;{\mu}m$ and the pattern was arrayed as $4{\times}4$. ZnO nanowires were grown on the Au catalyst pattern by the aid of Au liquid phase. The orientation of the ZnO nanowires was vertical on the whole. Sufficient brightness was obtained when the electric field was $5.4\;V/{\mu}m$ and the emission current was $5\;mA/cm^2$. The threshold electric field was $5.4\;V/{\mu}m$ in the $4{\times}4$ array of ZnO nanowires, which is quite lower than that of the nanowires grown on the flat Si substrate. The lower threshold electric field of the patterned ZnO nanowires could be attributed to their vertical orientation of the ZnO nanowires.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.12
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• pp.8-14
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• 2011

The optimal geometry of the gate field plate in AlGaN/GaN-on-Si HEMT has been proposed using two-dimensional device simulation to achieve a high breakdown voltage for a given gate-to-drain distance. It was found that the breakdown voltage was drastically enhanced due to the reduced electric field at the gate corner when a gate field plate was employed. The electric field distribution at the gate corner and the field plate edge was investigated as functions of field plate length and insulator thickness. According to the simulation results, the electric field at the gate corner can be successfully reduced even with the field plate length of 1 ${\mu}m$. On the other hand, when the field plate length is too long, the distance between field plate and drain electrode is reduced below a critical level, which eventually lowers the breakdown voltage. The highest breakdown voltage was achieved with the field plate length of 1 ${\mu}m$. According to the simulation results varying the $SiN_x$ film thickness for the fixed field plate length of 1 ${\mu}m$, the optimum thickness range of the $SiN_x$ film was 200 - 300 nm where the electric field strength at the field plate edge counterbalances that of the gate corner.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.957-960
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• 2003

We have studied the influence of rubbing directions on electro-optic characteristics of the fringe field driven hybrid aligned nematic liquid crystal (LC) cell by computer simulation. When a LC with positive dielectric anisotropy is used, the results show that the driving voltage and transmittance decreases as the rubbing direction with respect to horizontal electric field direction increases. The reason for decrease in light transmission is the reduction of twist angle and increase of tilt angle on the center of common electrode. In this paper, we have studied how the rubbing angle effects on the transmittance of the cell by investigating a distribution of electric field and LC director.