• Journal of the Korean Ceramic Society
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• v.56 no.1
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• pp.91-97
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• 2019

The effect of different Ni-containing additives on the sintering behavior and electric conductivity of the proton conducting electrolyte $BaCe_{0.35}Zr_{0.5}Y_{0.15}O_{3-{\delta}}$ (BCZY5) was investigated. Ni-doped, NiO-added, and $BaY_2NiO_5$(BYN)-added (all 4 mol%) BCZY5 samples were prepared by the solid state synthesis method and sintered at $1400^{\circ}C$ for 6 h. Among the three samples, the onset of densification was observed at the lowest temperature for NiO-added BCZY5, which is attributed to the formation of an intermediate phase at a low melting temperature. The BYN-added sample, where no consumption of the constitutional elements of the electrolyte was expected during sintering, exhibited the highest electrical conductivity whereas the doped sample had the lowest conductivity. The electrical conductivities at $500^{\circ}C$ under humid argon atmosphere were measured to be 2.0, 4.8, and $6.2mS{\cdot}cm^{-1}$ for Ni-doped and NiO- and BYN-added samples, respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.4
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• pp.176-182
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• 2014

We intended to prepare $Mg_3Sb_2$ compound bodies through solid state reactive sintering after cold-pressing mixtures of elementary Mg and Sb powders and investigated the crystal phases of the sintered bodies according to Mg/Sb mole ratios and reaction temperatures. The $Mg_3Sb_2$ bodies sintered at the temperatures of 773~843 K showed typical crystalline phases of $Mg_3Sb_2$ compounds, but their diffraction angles in XRD patterns were slightly different along with the vertical axis of the bodies obtained. All the bottom parts of the sintered $Mg_3Sb_2$ bodies were composed of the typical crystalline phases of $Mg_3Sb_2$ compounds and their diffraction angles were completely in accord with those of the ${\alpha}-Mg_3Sb_2$ phase, when Mg : Sb = 3.15 : 1.85 at 823 K, or when the Mg moles were greater than or equal to 3.10 at 843 K. It was considered that the slightly remaining Mg phases were formed by precipitation from ${\alpha}-Mg_3Sb_2$ phases during the solidification process of liquid phase.

• Applied Chemistry for Engineering
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• v.8 no.6
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• pp.994-999
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• 1997

The sintering properties of hydroxyapatite isolated from tuna bone and hydroxyapatite-containing wollastonite sintered by solid-state reaction was investigated. As the sinterability of hydroxyapatite dependent upon the particle size by dry milling, it showed a sintering. But the hydroxyapatite-containing wollastonite was appeared good sinterability. On X-ray measurements, the major phases of hydroxyapatite-containing wollastonite by solid state reaction at $1250^{\circ}C$ were identified as hydroxyapatite and pseudowollastonite(${\alpha}-CaSiO_3$). And the phases appeared as whitlockite [$Ca_3(PO_4)_2$] by decomposition of hydroxyapatite at higher temperature above $1250^{\circ}C$. The shapes of microstructure on SEM images changed from porous to dense bulk by elevating temperature. The mean bending strength of hydroxyapatite-containing wollastonite sintered by solid-state reaction at $1300^{\circ}C$ was about 18 MPa, it was close to the cancellous bone's maximum strength, 20 MPa.

• The Journal of Natural Sciences
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• v.8 no.1
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• pp.53-59
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• 1995

Effects of sintering additives and sintering temperatures on the sintering behavior and mechanical properties of SiC whisker reinforced alumina composites have been investigated in this study. Dense (>95% TD) composites were obtained by using 2 wt% $Y_2O_3$ as liquid phase sintering additive. But only porous composite could be obtained when the sintering additives were MgO and $TiO_2$, which were known as the sintering additives for solid state sintering of alumina. Bending strength and fracture toughness were enhanced by reinforcement of SiC whisker. It is belived from the microstructure investigation that the enhanced by strength and toughness could be attribute to the reinforcing and grain growth inhibition effects of SiC whisker. After HIP treatment, fully dense composites were obtained and further enhanced mechanical properties achieved.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.228-233
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• 2010

Mn-doped $Zn_2SiO_4$ phosphor particles having submicrometer sizes were synthesized by a solid-state reaction method using methyl hydrogen polysiloxane-treated ZnO, fumed $SiO_2$ and various Mn sources. The crystallization and photoluminescent properties of the phosphor particles were investigated by X-ray diffraction(XRD), scanning electron microscope(SEM), and by their photoluminescence(PL) spectra. Due to the effect of the dispersion and coherence of the methyl hydrogen polysiloxane-treated ZnO, the Mn-doped $Zn_2SiO_4$ particles were successfully obtained by a solid state method at $1000^{\circ}C$, and the maximum PL intensity of the prepared particles under vacuum ultra violet(VUV) excitation occurred at a Mn concentration of 0.02mol and a sintering temperature of $1000^{\circ}C$.

• Journal of Electrochemical Science and Technology
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• v.12 no.4
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• pp.398-405
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• 2021

To fabricate a full-scale pilot model of the cost-effective Na-(Ni,Fe)Cl₂ cell, a Na-beta-alumina solid electrolyte (BASE) was developed by applying a one-step synthesis cum sintering process as an alternative to the conventional solid-state reaction process. Also, Fe metal powder, which is cheaper than Ni, was mixed with Ni metal powder, and was used for cathode material to reduce the cost of raw material. As a result, we then developed a prototype Na-(Ni,Fe)Cl₂ cell. Consequently, the Ni content in the Na-(Ni,Fe)Cl₂ cell is decreased to approximately (20 to 50) wt.%. The #1 prototype cell (dimensions: 34 mm × 34 mm × 235 mm) showed a cell capacity of 15.9 Ah, and 160.3 mAh g^-1 (per the Ni-Fe composite), while the #2 prototype cell (dimensions: 50 mm × 50 mm × 335 mm) showed a cell capacity of 49.4 Ah, and 153.2 mAh g^-1 at the 2^nd cycle.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.2
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• pp.73-77
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• 2024

The spinel-type oxide (Ni_x, Mn_y, Co_3-x-y)O₄ (NMC) is widely utilized as a material for temperature sensors with a negative temperature coefficient (NTC), finding applications across various industries including electric vehicle battery management systems. Typically, NMC is manufactured using solid-state reaction methods employing powders of Ni, Mn, and Co compounds, with the densification process through sintering recognized as a crucial factor determining the electrical properties of the temperature sensor material. In this study, NMC pellets were synthesized via solid-state reaction and their crystallographic and microstructural characteristics were investigated. Also, the activation energy for densification behavior during the sintering process was determined. According to the analysis results, the room temperature resistance of the NMC pellets was measured at 10.03 Kohm, with the sensitivity parameter, B-value, recorded at 3601.8 K, indicating their potential applicability as temperature sensors across various industrial fields. Furthermore, the activation energy for densification was found to be 273.3 ± 0.4 kJ/mol, providing valuable insights into the thermodynamic aspects of the sintering process of the NMC.

• Journal of the Korean Ceramic Society
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• v.31 no.5
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• pp.465-470
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• 1994

Fine, spherical (Zr, SN)TiO4 powders were prepared from the aqueous solution of metal chlorides by ultrasonic spray pyrolysis. Single phase (Zr, SN)TiO4 powders could be obtained above $700^{\circ}C$ (=temperature of the reactor) and all powders exhibited sizes in the range of 0.1 to 2.0 ${\mu}{\textrm}{m}$ and a narrow size distribution. The sintering properties of the prepared powders were better than those of the powders from solid-state reaction.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1271-1273
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• 1994

In the field of the optics, precise machine, semiconducting processing, the micro-positioning actuators are required for the control of position in the submicron range. In this study, PNN-PZN-PZT ceramics were fabricated by solid state reaction. The structural, dielectric and electric properties were investigated for sintering condition. The specimen sintered for 1hr at 1,150($^{\circ}C$), had the highest density and dielectric contant.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.7
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• pp.543-546
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• 2011

We studied sintering temperature to enhance the piezoelectric properties of $0.98(Na_{0.5}K_{0.5})NbO_3-0.02Li(Sb_{0.17}Ta_{0.83})O_3$+0.01wt%ZnO (hereafter NKN-LST+ZnO) lead free piezoelectric ceramics. The synthesis and sintering method were the conventional solid state reaction method and sintering was executed at $1,080\sim1,120^{\circ}C$. We found that NKN-LST+ZnO ceramics at optimal sintering temperature showed the improved piezoelectric properties at the optimal sintering temperature. The NKN-LST+ZnO ceramics show good performance with piezoelectric constant $d_{33}$= 153 pC/N sintered at $1,090^{\circ}C$. The results reveal that NKN-LST+ZnO ceramics are promising candidate materials for lead-free piezoelectric application.