• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.259-259
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• 2007

The low temperature sintering of dolomite type borates, $CaZr(BO_3)_2$[CZB] ceramics and their microwave dielectric properties were investigated The sintering temperature of CZB ceramics could be reduced from $1150^{\circ}C$ to $925^{\circ}C$ by the addition of sintering additive. $CaZrO_3$, $ZrO_2$ and $CaB_2O_4$ second phases were found in the CZB ceramics. The syntheses, sintering properties, microstructures, and dielectricnproperties of dolomite-type borates were examined by XRD, thermal analysis, electron microscopy, network analyzer, and the results are discussed intensively. The compatibility with silver electrode was also explored.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.799-802
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• 2002

For purer images in plasma display panel, a new dielectric compositions containing neodymium oxide were studied. In the present study, Pb-based compositions were used as mother glasses (PbO-$B_2O_3-SiO_2Nd_2O_3$) and thermal, dielectric, and optical properties were measured. As a result the new dielectric with a rare-earth oxide made selectively visible light penetrated and showed especially noticeable absorption properties at 585 nm that is surely related to the erroneous gas from Ne discharge. Thus, this light purple colored glass composition will help PDP to come true to get better imaging process.

• Korean Journal of Crystallography
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• v.11 no.4
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• pp.195-199
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• 2000

Ceramics based on CaTiO₃-NdAlO₃ solid solutions were synthesized in order to study their dielectric microwave properties. Microstructural analysis was performed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM) using different analytical methods such as energy-dispersive X-ray spectroscopy (EDXS). It was observed that the heating conditions during sintering and cooling strongly affect the microstructural development of CaTiO₃-NdAlO₃-based ceramics. Various types and concentrations of structural defects were identified, for example, dislocations, twins and/or antiphase boundaries. all such defects resulted in a degradation of the dielectric microwave properties, in particular the quality factor Q. Dielectric properties of CaTiO₃-NdAlO₃-based ceramics can be improved by an appropriate thermal treatment of ceramics which results in a decrease in the concentrations of the identified microstructural defects.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.5
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• pp.326-331
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• 2015

In this paper, we study the insulating properties of the liquid nitrogen(LN2) including the thermal bubbles. The shape of the thermal bubbles in accordance with the current change was observed in the 77 K and 65 K LN2. According to the temperature of liquid nitrogen, bubbles were generated differently. The round shape of the bubble is occurred in 77 K LN2. But the layer shape of bubble is occurred in 65 K LN2. When the bubbles present, the dielectric strength of liquid nitrogen is low. However, the breakdown patterns were different according to the electrode arrangement. AC breakdown voltage(BDV) was lower than the DC BDV due to the influence of bubbles. Therefore, the design of a high-voltage superconducting equipments should consider the bubbles.

• Proceedings of the KIEE Conference
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• 2008.05a
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• pp.183-184
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• 2008

The aim of this study is to find out the effects of thermal aging condition on dielectric strength and degree of crtstallinity of XLPE insulation. Thermal properties of XLPE insulation were investigated by DSC(differential scanning calorimetry) and dielectric strength were analyzed using AC BDV tester. Aging of XLPE samples were conducted through different four conditions. The degree of crtstallinity and AC BDV were changed by thermal history. From these results, it can be suggested that DSC and AC BDV test are suitable for diagnostic method of extra high voltage XLPE cable.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.7
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• pp.279-286
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• 2002

Linear and nonlinear complex permittivities were measured for copolymers of vinylidene cyanide(VDCN) with vinyl acetate(VAc), vinyl propionate(VPr), vinyl bezoate(VBz), styrene(St) and methyl methacrylate(MMA). Experimental results are well fitted by the function (equation omitted) except at low frequency where dc conduction dominates. The analysis of dielectric relaxation mechanism by combined knowledge about linear and nonlinear dielectric permittivities and dipoles give us informations about electrical and thermal motions in these copolymers. According to the analysis it could be found that the variation for temperature of the dielectric relaxation strength in these copolymers is related to the interaction between dipoles and the nonlinear dielectric effect factor R$_{s}$ is proportional to square of the dipolar correlation factor R$_{p}$././.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.5
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• pp.366-371
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• 2012

In this paper, fabricated by MEMS uncooled micro-bolometer detector for the study in the infrared sensitivity enhancement. Absorption layer SiOx-Metal series MDTF (metal-dielectric thin film) by high absorption rate and has a high thermal coefficient of resistance, low noise characteristics were implemented. Then MDTF were made in a vacuum deposition method. And MDTF for the analysis of the physical properties of silicon wafers were fabricated, TCR (temperature coefficient of resistance) value was made in order to measure the glass wafer and FT-IR (Fourier Transform Infrared spectroscopy) values were made in order to measure the germanium window. The analyzed results of MDTF -3 [%/K] has more characteristics of the TCR. And 8~12 um wavelength region close to 70% in the absorption characteristic.

• Journal of the Korean Society of Safety
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• v.17 no.4
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• pp.101-109
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• 2002

The electrical properties of polyethylene are changed by the superstructure. Such crystalline polymer as polyethylene or polypropylene changes crystallinity and products spherulite or trans-crystal when it is cooled slowly. In this study, after thermal treatment of LDPE at 100[${circ}C$], in silicone oil for an hour, we made specimens in order of slow cooling, water cooling, quenching according to cooling speed. Also, to study the influence of electrical properties due to the superstructure change, we analyzed physical properties and performed dielectric breakdown experiments using DC and impulse voltage Moreover we measured space charges in bulk using Laser Induced Pressure Pulse(LIPP) method. Trap level of specimen is 0.064[eV] at the low temperature region 0.31[eV] at the high temperature region in DC dielectric strength, 0.03[eV] at the low temperature region 0.0925[eV] at the high temperature region in impulse dielectric strength. As its result shows that the quantity of charges induced from the electrode surface increases with applied voltage time, and the distribution of space charges in samples increases the quantity of charges in proportion to applied voltage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.290-293
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• 1999

(Ba$_{0.5}$Sr$_{0.5}$)TiO$_3$ thin films were fabricated at different RTA temperatures and thicknesses by Sol-Gel method. Solution consisting of acetate powders and titanium isopropoxide in a mixture of acetic acid and ethylene glycol were spin coated onto Pt/Ti/SiO$_2$/Si substrates. The films were annealed in the temperature range of 650~80$0^{\circ}C$ for 3 minutes by rapid thermal annealing. These BST thin films were fully crystallized at 75$0^{\circ}C$ and showed a maximum dielectric constant value of $\varepsilon$$_{r}$=~468 and dielectric loss was ~0.025 at a thickness of approximately 4000$\AA$.EX>.>.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.6
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• pp.215-219
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• 2020

After the specimen of A-site defect double Perovskite La1/3TaO3 single crystal was manufactured, the dielectric properties have been studied between the temperature range of 10 and 800 K. Under 500 K, a paraelectric behavior has been shown, and above 550 K, a dielectric anomaly and a thermal history of dielectric constant has been shown. An activation energy by measurement of ac-conductivity has been the largest with 1.83 eV in the areas below 560 K, 0.35 eV in the areas of 560~690 K, and 0.28 eV in the areas of high temperature above 690 K. From these results, it is assumed that in the areas below 500 K, La3+-ion and vacancy-site are arranged in disorder to maintain a paraelectric phase. And in the areas near 560 K with the highest activation energy, a dielectric anomaly is attributes to rearrangement of La3+-ion due to conduction to vacancy-site or jumping.