• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.76-79
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• 2000

The $Ba(Zn_{1/3}Ta_{2/3})O_3$ ceramics were prepared by conventional mixed oxide method. The structural properties of the BZT ceramics with the sintering temperature were investigated by XRD, SEM. The BZT ceramics have a complex-perovskite structure. The BZT ceramics sintered at $1550^{\circ}C$ had a superstructure plane of BZT(100). Increasing the sintering temperature, the bulk density and ordering were increased. The bulk density of the BZT ceramics sintered at $1550^{\circ}C$ was $7.50[g/cm^3]$. Increasing the sintering temperature, the average grain size were increased and pore were decreased.

• Korean Journal of Materials Research
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• v.17 no.6
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• pp.298-302
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• 2007

The electrical properties and its stability of Zn-Pr-Co-Cr-Tb-based varistors were investigated for different sintering temperatures. As the sintering temperatures increased, the varistor voltage decreased in the range of $705.2{\sim}299.1$ V/mm, the nonlinear coefficient decreased in the range of $42.4{\sim}31.7$, and the leakage current was in the range of $1.0{\sim}1.7\;{\mu}A$. The stability of electrical characteristics increased with the increase of sintering temperature. The varistors sintered at $1350^{\circ}C$ marked the high electrical stability, with $%\Delta$ $V_{1mA}=+0.1%,\;%\Delta{\alpha}=+3.2%$, and $%{\Delta}I_L=+117.6%$ for DC accelerated aging stress state of $0.95V_{1mA}/150^{\circ}C/24\;h$.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.3
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• pp.97-102
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• 2005

This research was a fundamental study for the low temperature sintering of PZTN by glass phase transient processing. To lower the sintering temperature, the glass phase Processing was used. Also to improve the electrical properties, the transient processing was utilized. After characterization, the various analytic techniques, such as Archimedes method for the measuring densification, x-ray diffraction patterns for the quantitative analysis of crystalline phases were utilized. Also the dielectric constant, dissipation factor, and piezoelectric coefficients were measured to evaluate the PZTN sintered at the $950^{\circ}C$ and $1050^{\circ}C$. This was confirmed that the sintering temperature of PZTN was reduced by $950^{\circ}C$ and the electrical properties were improved by the transition processing. Therefore, the glass phase transient processing can be applicable to low the sintering temperature with the dielectric and piezoelectric properties.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.5
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• pp.453-457
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• 2008

In this thesis, piezoelectric properties and sintering properties of PCW-PNN-PZT+0.5 wt%$MnO_2$ ceramics adding $B_2O_3$ after creating the specimens with a general method. The lattice constant from the analysis of crystal structure showed that the crystal structure of ceramic features both rhombohdral and tetragonal structures and that the pychlore structure was decreased with the increase of the sintering temperature. The electromechanical coupling coefficient showed its maximum of 31 % in the sintered specimens at $1050^{\circ}C$, and its minimum of 20 % in the sintered specimens at $1150^{\circ}C$. The mechanical quality coefficient marked the maximum of 139 at the sintering temperature of $1150^{\circ}C$.

• Journal of Powder Materials
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• v.24 no.2
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• pp.108-114
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• 2017

We fabricate fine (<$20{\mu}m$) powders of $Bi_{0.5}Sb_{1.5}Te_3$ alloys using a large-scale production method and subsequently consolidate them at temperatures of 573, 623, and 673 K using a spark plasma sintering process. The microstructure, mechanical properties, and thermoelectric properties are investigated for each sintering temperature. The microstructural features of both the powders and bulks are characterized by scanning electron microscopy, and the crystal structures are analyzed by X-ray diffraction analysis. The grain size increases with increasing sintering temperature from 573 to 673 K. In addition, the mechanical properties increase significantly with decreasing sintering temperature owing to an increase in grain boundaries. The results indicate that the electrical conductivity and Seebeck coefficient ($217{\mu}V/K$) of the sample sintered at 673 K increase simultaneously owing to decreased carrier concentration and increased mobility. As a result, a high ZT value of 0.92 at 300 K is achieved. According to the results, a sintering temperature of 673 K is preferable for consolidation of fine (<$20{\mu}m$) powders.

• Korean Journal of Materials Research
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• v.25 no.1
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• pp.37-42
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• 2015

The effect of sintering temperature on the microstructure, electrical and dielectric properties of (V, Mn, Co, Dy, Bi)-codoped zinc oxide ceramics was investigated in this study. An increase in the sintering temperature increased the average grain size from 4.7 to $10.4{\mu}m$ and decreased the sintered density from 5.47 to $5.37g/cm^3$. As the sintering temperature increased, the breakdown field decreased greatly from 6027 to 1659 V/cm. The ceramics sintered at $900^{\circ}C$ were characterized by the highest nonlinear coefficient (36.2) and the lowest low leakage current density ($36.4{\mu}A/cm^2$). When the sintering temperature increased, the donor concentration of the semiconducting grain increased from $2.49{\times}10^{17}$ to $6.16{\times}10^{17}/cm^3$, and the density of interface state increased from $1.34{\times}10^{12}$ to $1.99{\times}10^{12}/cm^2$. The dielectric constant increased greatly from 412.3 to 1234.8 with increasing sintering temperature.

• Journal of the Korean Ceramic Society
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• v.35 no.11
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• pp.1203-1211
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• 1998

The microwave sintered BaTiO3 samples were obtained by using the microwave sintering device which can precisely control the sintering temperature and the sinter time by using IR optical thermometer and PID temperature controller. During microwave sintering the internal temperature of samples were mesur-ed by the optical fiber thermometer to compare the sintering behaviors between microwave- and con-ventionally sintered ones. The former showed the faster rate of grain growth with sintering time and the larger grain size than the latter. Also they showed the similar pattern of dielectric properties with tem-perature changes from 2$0^{\circ}C$ to 16$0^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.282-286
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• 2003

We investigated the effects of calcination temperature and sintering additives on the sintering behaviors and microwave dielectric properties of $(Zn_{0.8}Mg_{0.2})TiO_3$. Highly densified samples were obtained at the sintering temperatures below $1000^{\circ}C$ with additions of 0.45 wt.% $Bi_2O_3$ and 0.55 wt.% $V_2O_5$. From the examination of the existing phases and microstructures before and after sintering of $(Zn_{0.8}Mg_{0.2})TiO_3$ system calcined at the various temperatures ranging from $800^{\circ}C$ to $1000^{\circ}C$, it was found that high $Q{\times}f_o$ values were obtained when unreacted or second phases in calcined body were reduced. When calcined at $1000^{\circ}C$ and sintered at $900^{\circ}C$, it consists of hexagonal as a main phase with uniform microstructure and exhibits $Q{\times}f_o$ value of 42,000 GHz and dielectric constant of 22.

• Korean Journal of Materials Research
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• v.32 no.4
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• pp.181-185
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• 2022

In this study, phase-pure titanium dioxide TiO₂ ceramics are sintered using standard high-temperature solid-state reaction technique at different temperatures (1,000, 1,100, 1,200, 1,300, 1,400 ℃). The effect of sintering temperature on the densification and impedance properties of TiO₂ ceramics is investigated. The bulk density and average grain size increase with the increase of sintering temperature. Impedance spectroscopy analysis (complex impedance Z^* and complex modulus M^*), performed in a broad frequency range from 100 Hz to 10 MHz, indicates that the TiO₂ ceramics are dielectrically heterogeneous, consisting of grains and grain boundaries. The complex impedance Z^* -plane indicates the resistance of grains of the TiO₂ ceramics increases with increasing sintering temperature, while that of grain boundaries develops in the opposing direction. The complex modulus M^*-plane shows a grain capacitance that seems to be independent of the sintering temperature, while that of the grain boundaries decreases with increasing sintering temperature. These results suggest that different sintering temperatures have effects on the microstructure, leading to changes in the impedance properties of TiO₂ ceramics.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.5
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• pp.37-44
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• 2014

The physical, mechanical and freezing and thawing properties of non cement porous vegetation concrete using non-sintering inorganic binder have been evaluated in this study. Four types of porous vegetation concrete according to the binder type is evaluated. The pH value, void ratio, compressive strength, repeated freezing and thawing properties were tested. The test results indicate that the physical, mechanical and repeated freezing and thawing properties of porous vegetation concrete using the non-sintering inorganic binder is increased or equivalent compared to the porous vegetation concrete using the blast furnace slag + cement and hwang-toh + cement binders. Also, Vegetation monitoring test results indicate the porous vegetation concrete using the non-sintering inorganic binder have increasing effects of vegetation growth.