• Title/Summary/Keyword: Solid state sintering

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Carbon Dioxide Sorption Properties and Sintering Behavior of Lithium Zirconate Prepared by Solid-State Reaction (고상반응에 의하여 제조된 Li2ZrO3의 이산화탄소 흡수 및 소결 특성)

  • Woo, Sang-Kuk;Lee, Shi-Woo;Yu, Ji-Haeng
    • Journal of the Korean Ceramic Society
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    • v.43 no.5 s.288
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    • pp.309-314
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    • 2006
  • We synthesized lithium zirconate using solid-state reaction and analyzed thermal properties (TG/DTA) of starting materials and the synthesized one. When $Li_2ZrO_3$ powder was exposed to $CO_2$ environment at $500^{\circ}C$, 93% of the theoretical absorption weight was gained within 280 min with fairly high sorption rate. Almost all the absorbed $CO_2$ was generated by heating the sample to $800^{\circ}C$. We also investigated densification behavior of $Li_2ZrO_3$ under $CO_2$ environment. By sintering $Li_2ZrO_3$ at $760^{\circ}C$ using 2-step process, we obtained dense product, composed mainly of $Li_2ZrO_3\;and\;ZrO_2$, with relative density of 92%.

Electrolyte Preparation and Characteristics of La1-xSrxMnO3 for Solid Oxide Fuel Cell (고체전해질형 연료전지용 전해질 제작 및 La1-xSrxMnO3의 특성에 관한 고찰)

  • Rim, Hyung-Ryul;Lee, Ju-Seong
    • Applied Chemistry for Engineering
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    • v.7 no.1
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    • pp.9-17
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    • 1996
  • Solid oxide electrolytes of 8mol% YSZ($Y_2O_3$ stabilized zirconia) were prepared at various sintering conditions and their ionic conductivities were measured. The highest ionic conductivity of $10^{-1}S.cm^{-1}$ was obtained when the sintering temperature was 1400oC and the sintering time was 10hr. Also the cathode material, $La_{1-x}Sr_xMnO_3$ was prepared by solid state reaction method and the overpotential, electrical conductivity, and charge transfer resistance between cathode material and YSZ electrolyte were studied. It was found that the optimum doping content of Sr for La was 50mo1%.

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Effect of Abnormal Grain Growth on Ionic Conductivity in LATP (LATP 내 비정상 입자성장이 이온 전도도에 미치는 영향)

  • Hyungik Choi;Yoonsoo Han
    • Journal of Powder Materials
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    • v.31 no.1
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    • pp.23-29
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    • 2024
  • This study investigates the effect of the microstructure of Li1.3Al0.3Ti1.7(PO4)3 (LATP), a solid electrolyte, on its ionic conductivity. Solid electrolytes, a key component in electrochemical energy storage devices such as batteries, differ from traditional liquid electrolytes by utilizing solid-state ionic conductors. LATP, characterized by its NASICON structure, facilitates rapid lithium-ion movement and exhibits relatively high ionic conductivity, chemical stability, and good electrochemical compatibility. In this study, the microstructure and ionic conductivity of LATP specimens sintered at 850, 900, and 950℃ for various sintering times are analyzed. The results indicate that the changes in the microstructure due to sintering temperature and time significantly affect ionic conductivity. Notably, the specimens sintered at 900℃ for 30 min exhibit high ionic conductivity. This study presents a method to optimize the ionic conductivity of LATP. Additionally, it underscores the need for a deeper understanding of the Li-ion diffusion mechanism and quantitative microstructure analysis.

Liquid-Phase Sintering of $YBa_2Cu_3O_x$ Ceramic Superconductor and Grain Size Control Using $Y_2BaCuO_5$ ($YBa_2Cu_3O_x$초전도체의 액상 소결과 $Y_2BaCuO_5$를 이용한 입자 크기 제어)

  • 노광수;이정용;위당문
    • Journal of the Korean Ceramic Society
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    • v.27 no.3
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    • pp.423-429
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    • 1990
  • YBa2Cu3Ox ceramics superconductors fabricated using solid state reaction usually contain second phases, such as BaCuO2 and CuO. These second phases are located long the grain boundaries and enhance the abnormal growth of YBa2Cu3Ox grains and, consequently, generate the microcracks. These second phaases were reduced by adding Y2BaCuO5 into solid state reacted YBa2Cu3Ox ceramics. Y2BaCuO5 reacts with grain boundary second phases and reduces the grian size of the ceramics. It was observed the critical current density was improved by adding Y2BaCuO5 into solid state reacted YBa2Cu3Ox ceramic superconductor.

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Synthesis of Intermetallics and Nanocomposites by High-Energy Milling

  • Bernd F. Kieback;H. Kubsch;Alexander Bohm;M. Zumdick;Thomas Weissgaerber
    • Journal of Powder Materials
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    • v.9 no.6
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    • pp.416-421
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    • 2002
  • Elemental powders are used in high energy milling processes for the synthesis of new compounds. The low temperature solid state reactions during milling in inert gas atmosphere may result in intermetallic phases, carbides, nitrides or silicides with a nanocrystalline structure. To obtain dense materials from the powders a pressure assisted densification is necessary. On the other side the defect-rich microstructure can be used for activated sintering of elemental powder mixtures to obtain dense bodies by pressureless sintering. Results are discussed for nanocrystalline cermet systems and for the sintering of aluminides and silicides.

Preparation of Sintering Aid for Li7La3Zr2O12 Solid Electrolyte by Heat-treatment of Polymeric Precursors Containing Li and B (Li과 B이 포함된 폴리머 전구체의 열처리에 의한 Li7La3Zr2O12 고체전해질의 소결조제 합성)

  • Shin, Ran-Hee;Ryu, Sung-Soo
    • Journal of Powder Materials
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    • v.25 no.2
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    • pp.151-157
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    • 2018
  • In this study, the compound $Li_3BO_3$ (LBO) is intended to be prepared by a polymeric complex method as a sintering aid for the densification of $Li_7La_3Zr_2O_{12}$ (LLZ) solid electrolyte. A polymeric precursor containing Li and B is heat-treated in an air atmosphere at a temperature range between $600^{\circ}C$ and $800^{\circ}C$. Instead of LBO, the compound $Li_{2+x}C_{1-x}B_xO_3$ (LCBO) is unexpectedly synthesized after a heat-treatment of $700^{\circ}C$. The effect of LCBO addition on sintering behavior and ion conductivity of LLZ is studied. It is found that the LCBO compound could lead to significant improvements in the densification and ionic conductivity of LLZ compared to pure LLZ. After sintering at $1100^{\circ}C$, the density of the LLZ-12wt%LBO composite is $3.72g/cm^3$, with a high Li-ion conductivity of $1.18{\times}10^{-4}Scm^{-1}$ at $28^{\circ}C$, while the pure LLZ specimen had a densify of $2.98g/cm^3$ and Li-ion conductivity of $5.98{\times}10^{-6}Scm^{-1}$.

Effect of Agglomeration of $Nb_20_5$ on Formation Reaction, Sintering and Dielectric Properties in$Pb(MG_{1/3}Nb_{2/3})O_3$ (원료분체 $Nb_20_5$의 응집상태가 $Pb(MG_{1/3}Nb_{2/3})O_3$소결, 유전특성에 미치는 영향)

  • 조영국;김진호;박병옥;조상희
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.2 no.1
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    • pp.51-59
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    • 1992
  • Effect of agglomeration of $Nb_20_5$ of the same primary particle size on formation reaction and sintering of $Pb(Mg_{1/3}\;Nb_{2/3})O_3$ was examined. Both solid state reaction and molten salt synthesis were adopted. With decreasing agglomeration of $Nb_20_5$ increased the rate of formation reaction of perovskite PMN in solid state reaction, but had little influence in molten salt synthesis. It was concluded that the increase in the inhomogeneity of the dispersion state of intermediate pyrochlore with increasing agglomeration of $Nb_20_5$ retarded the formation reaction of perovskite PMN in solid state reaction, while had little influnce in molten salt synthesis due to its solution - precipitation mechanism -mainly depends on powder surface area.

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Effect of Pyrochlore Phase on Electric Properties for PNN-PT-PZ Piezoelectric Ceramics (PNN-PT-PZ계 압전세라믹스의 전기적 특성에 미치는 Pyrochlore 상의 영향)

  • 이기태;남효덕
    • Journal of the Korean Ceramic Society
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    • v.31 no.9
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    • pp.1030-1036
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    • 1994
  • The ceramics in the system 0.5[Pb(Ni1/3Nb2/3)O3]-0.5[0.65PbTiO3-0.35PbZrO3] were prepared by conventional solid state reaction method, double calcined method (columbite precursor method) and flux method using NaCl-KCl. Amount of pyrochlore phase for the calcined powders, sintering charateristrics, dielectric and piezoelectric properties were then investigated. Sintering temperature was 1000~120$0^{\circ}C$ and in case of flux method, the amount of flux to oxide was 1 : 1 mole ratio. The dielectric and piezoelectric properties of ceramics prepared by double calcined method and flux method were found to be better than those by conventional method. It was also possible to lower sintering temperature and reduce the amount of pyrochlore phase either by double calcined method or flux method. But with increasing sintering temperature, the difference in characteristrics due to diffrent fabrication method gradually.

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Electrochemical Properties of Spinel $LiMn_2O_4$Synthesized at Various Sintering Condition (열처리 조건에 따른 스피넬 $LiMn_2O_4$의 전기 화학적 특성)

  • 한태희;박종광;한병성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.12 no.1
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    • pp.50-55
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    • 1999
  • We have investigated the $LiMn_2O_4$system as an cathode material for lithium rechargeable batteries. $LiMn_2O_4$spinel oxides have been synthesized by a solid state methode. We varied sintering time at a fixed sintering temperature of 75$0^{\circ}C$. In order to investigate the electrochemical properties of prepared $LiMn_2O_4$we assembled three-electrode cells using the working electrode as active material and Li metal as the counter and reference electrodes. The electrolyte was 1 M LiPE$_{6}$-EC:DEC(1:1 by volume). The particle size of sample synthesized at 75$0^{\circ}C$ ranged about 60$\mu m$. The discharge capacity of a cell involving spinel $LiMn_2O_4$ increased with increasing sintering time.e.

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