• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.3
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• pp.257-262
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• 2001

Single crystalline films of La doped YIG(yttrium iron garnet) were grown by the liquid phase epitaxy. The lattice constants of films obtained by DCD(double crystalline diffractometer) measurement increased with increasing La contents in films. In particular, lattice constants of films grown wiht Y/La=20 solution were nearly same as those of GGG (gadolinium gallium garnet) substrate. The saturation magnetization measured with VSM (vibrating sample magnetometer) was about 1750Gauss which is the same as that of pure YIG irrespective of La contents in films. FMR(ferromagnetic resonance) linewidth of La doped YIG was smaller than that of pure YIG. Since appropriate La doping decreases the lattice mismatch between film and substrate, the FMR linewidth was Y/La=20 in this experiment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.89-92
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• 2000

Liquid Phase Epitaxy 법을 이용하여 La이 첨가된 YIG(Yitrium Ion Garnet)막을 성장시켰다. X선 회절 분석을 이용하여 La의 첨가량을 변화시키며 제조된 막의 격자상수를 조사한 결과, La의 첨가량이 증가함에 따라 성장된 막의 격자상수도 증가하였으며 Y/La이 20인 경우, 막의 격자상수가 기판으로 사용한 GGG의 격자상수와 일치하였다. VSM(Vibration Sample Magnetometer)를 이용하여 구한 막의 포화자화 값은 La의 첨가량과 관계없이 순수한 YIG의 경우와 같은 값인 1750정도로 거의 일정하였다. FMR(Ferro Magnetic Resonance) 측정장치를 이용한 막의 강자성 공명선폭을 측정결과 막의 공명선폭은 La의 첨가량과 관계없이 모든 경우에 순수한 YIG보다 감소하였다. 실험범위내의 La의 첨가에 대해서 기판과의 격자불일치가 순수한 YIG의 경우보다 감소하기 때문이다. La의 첨가량이 많은 조건에서 성장시킨 막은 공명선폭이 크고 두께의 증가에 따라서 선폭이 증가하였으며, Y/La가 20과 30일 때 성장시킨 막에서는 공명선폭의 절대값도 작고 두께에 따른 공명선폭의 변화도 관찰되지 않았다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1377-1378
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• 2007

본 논문에서는 초고압 케이블에서 절연재료로 사용되고 있는 가교폴리에틸렌(Cross-Linked Polyethylene; xLPE)에 침전극의 기울기와 인가전압의 변화에 따른 전계분포와 방전특성을 경계요소법에 의한 3차원 시뮬레이션과 부분방전장치를 통하여 해석하여, 기울기가 $45^{\circ}$에서 전계가 집중되는 현상을 확인하였다.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.312-318
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• 2018

We investigated the effect of postharvest treatments of calcium chloride, lysophosphatidyl ethanolamine (LPE) or 1-methylcyclopropene (1-MCP) on fruit quality during simulated marketing in Asian pear (Pyrus pyrifolia Nakai). 'Whangkeumbae' pear fruits were immersed in 0.25, 0.5 or 1.0% $CaCl_2$ solution with or without ultrasound (40kHz) at $25^{\circ}C$ for 3min followed by storage at $1^{\circ}C$ for 30 days simulated as abroad exportation. After simulated marketing at $25^{\circ}C$ and 80% relative humidity (RH) up for 10 days, quality parameters were evaluated. Results indicated that the ultrasound and $CaCl_2$ treatment had a synergic effect on keeping the green skin color which showed lower $a^*$ value. The combination treatment of ultrasound and 0.5% and 1.0% $CaCl_2$ significantly reduced internal browning disorders, although severe skin blemish disorder (20-23%) occurred in 1.0% $CaCl_2$ treatment. 'Wonhwang' pears were immersed in 1,000ppm LPE for 3 minutes or were fumigated in 1,000 ppb 1-MCP for 12 hours, respectively. The results of the fruit quality survey during the 21 days of distribution period are as follows. The 1-MCP treatment was maintained at a constant flesh firmness of 33N or higher during the distribution period. The LPE treated fruits had a lower physiological disorder index than the untreated group, but showed a relatively higher value than the 1-MCP treated group. In the case of 1-MCP treatment, the fruit respiration rate was significantly lower than of untreated control ($6.0mL{\cdot}kg^{-1}{\cdot}hr^{-1}$) during the simulaed marketing period. Consequently, it was expected that the postharvest treatments of 0.5% calcium chloride in pararell with ultrasound and 1-MCP fumigation can help to maintain Asian pear quality during distribution period.

• Korean Journal of Materials Research
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• v.4 no.6
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• pp.687-694
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• 1994

Heteroepitaxial InP/GaAs layers were grown using the selective liquid phase epitaxy (SLPE) technique. It was observed that the optimum LPE conditions were $660^{\circ}C$ growth temperature, $5^{\circ}C$ supercooling, and $0.4^{\circ}C$/min cooling rate. Maximum expitaxial layer overgrowth (ELO) of 110-160$\mu \textrm{m}$ was obtained when the seed was aligned along (112) orientation. Initial melt-back of the substrate was observed but limited to the seed region so that flat In-Ga-As-P layers were grpwn throughout the GaAs substrates. The InP/GaAs heteroepitaxial structure could be obtained by growing an additional InP layer on top of the In-Ga-As-P layer.

• Clean Technology
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• v.28 no.4
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• pp.293-300
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• 2022

The remarkable mechanical, electrical, and thermal properties of graphene have recently sparked tremendous interest in various research fields. One of the most promising methods to produce large quantities of graphene dispersion is liquid-phase exfoliation (LPE) which utilizes ultrasonic waves or shear stresses to exfoliate bulk graphite into graphene flakes that are a few layers thick. Graphene dispersion produced via LPE can be transformed into graphene ink to further boost graphene's applications, but producing high-quality graphene more economically remains a challenge. To overcome this shortcoming, an advanced LPE process should be developed that uses relatively cheap natural graphite as a graphene source. In this study, a flow-LPE process was used to exfoliate natural graphite to produce graphene that was three times cheaper and seven times larger than synthetic graphite. The optimal exfoliation conditions in the flow-LPE process were determined in order to produce high-quality graphene flakes. In addition, the structural and electrical properties of the flakes were characterized. The electrical properties of the exfoliated graphene were investigated by carrying out an ink formulation process to prepare graphene ink suitable for inkjet printing, and fabricating a printed graphene pattern. By utilizing natural graphite, this study offers a potential protocol for graphene production, ink formulation, and printed graphene devices in a more industrial-comparable manner.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.518-520
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• 1987

The semiconductor-metal-semiconductor structure is considered to be promising for high speed electronic devices. To realize this, the selective LPE and the proper design of epitaxial mask were adopted. Enhanced As diffusion made it possible to grow GaAs over W on GaAs. Buried W Schottky diode was fabricated and the rectifying I-Y characteristics were obtained.

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.110.1-110
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• 2002

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.810-814
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• 1995

LPE growth experiment were carried out to make garnet crystal for Faraday rotator and we have evaluated the characteristics of Faraday rotator by a measurement system which is consist of electromagnet and optical components, also done Laue pattern analysis. The thickness of garnet film was $180\;\mu\textrm{m}$ and the Faraday rotation of this film was 388 deg/Cm at wavelength $1.55\;\mu\textrm{m}$, room temperature.

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.206-209
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• 1989

It has been that, above $600^{\circ}C$, a cover crystal is essential for protecting InP substrate from severe gas etching during soaking procedure and shown that the melt back rate of substrate crystal in In solvent is about 0.90${\mu}{\textrm}{m}$/sec at 635$^{\circ}C$, 0.57${\mu}{\textrm}{m}$/sec at 615$^{\circ}C$ and 0.37${\mu}{\textrm}{m}$/sec at 595$^{\circ}C$.