• Transactions on Electrical and Electronic Materials
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• v.13 no.5
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• pp.225-228
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• 2012

In order to synthesize LED phosphor materials, we have applied three novel synthesis techniques, "melt synthesis", "fluidized bed synthesis" and "vapor-solid hybrid synthesis", in contrast with the conventional solid state reaction technique. These synthesis techniques are also a general and powerful tool for rapid screening and improvements of new phosphor materials.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1084-1085
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• 2006

We studied formation of nanostructured $TiB_2$-Cu composites under shock wave conditions. We investigated the influence of preliminary mechanical activation (MA) of Ti-B-Cu powder mixtures on the peculiarities of the reaction between Ti and B under shock wave. In the MA-ed mixture the reaction proceeded completely while in the non-activated mixture the reagents remained along with the product . titanium diboride. The size of titanium diboride particles in the central part of the compact was 100-300 nm.

• Journal of the Korean Ceramic Society
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• v.32 no.2
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• pp.234-238
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• 1995

MgFe2O4 formation, grain growth in Fe2O3, Fe solid-solution limit in MgO for MgO-Fe2O3 mixture were studied by means of investigating the distribution of phases and compositions in reaction area between MgO and Fe2O3. The reaction area at equlibrium was composed with MgO-FexO matrix and MgFe2O4 precipitation, MgFe2O4 was formed by precipitating from MgO-FexO matrix dependent on oxygen partial pressure. Fe contents was exponentially decreased with diffusion distance in MgO single crystal, and thus Fe solid-solution limitation in MgO was about 4mol%. The grain growth rate in Fe2O3 base was increased with Mg contents diffused from MgO single crystal.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.581-584
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• 2005

Ion beam processing is one of the key technologies to realize mastless and resistless sub 50nm nano fabrication. Unwanted effects, however, may occur since an energetic ion can interact with a target surface in various ways. Depending on the ion energy, the interaction can be swelling, deposition, sputtering, re-deposition, implantation, damage, backscattering and nuclear reaction. Sputtering is the fundamental mechanisms in ion beam induced direct patterning. Re-deposition and backscattering are unwanted mechanisms to avoid. Therefore understanding of ion beam-solid interaction should be advanced for further ion beam related research. In this paper we simulate some important interaction mechanisms between energetic incident ions and solid surfaces and the results are compared with experimental data. The simulation results are agreed well with experimental data.

• Bulletin of the Korean Chemical Society
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• v.14 no.5
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• pp.614-618
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• 1993

The photoacid generation efficiency of four N-hydroxyphthalimide sulfonate derivatives was studied by photo-crosslinking reaction of poly(glycidyl methacrylate) in solid film state. The relative photoacid generation efficiency was increased in the order of N-hydroxyphthalimide methanesulfonate > -toluenesulfonate > -nitrobenzenesulfonate > -dinitrobenzensulfonate, and the reaction was efficiently sensitized by benzophenone suggesting that this photoreactions is likely to proceed through its triplet excited state.

• Journal of Powder Materials
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• v.30 no.4
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• pp.324-331
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• 2023

Lithium (Li) is a key resource driving the rapid growth of the electric vehicle industry globally, with demand and prices continually on the rise. To address the limited reserves of major lithium sources such as rock and brine, research is underway on seawater Li extraction using electrodialysis and Li-ion selective membranes. Lithium lanthanum titanate (LLTO), an oxide solid electrolyte for all-solid-state batteries, is a promising Li-ion selective membrane. An important factor in enhancing its performance is employing the powder synthesis process. In this study, the LLTO powder is prepared using two synthesis methods: sol-gel reaction (SGR) and solid-state reaction (SSR). Additionally, the powder size and uniformity are compared, which are indices related to membrane performance. X-ray diffraction and scanning electron microscopy are employed for determining characterization, with crystallite size analysis through the full width at half maximum parameter for the powders prepared using the two synthetic methods. The findings reveal that the powder SGR-synthesized powder exhibits smaller and more uniform characteristics (0.68 times smaller crystal size) than its SSR counterpart. This discovery lays the groundwork for optimizing the powder manufacturing process of LLTO membranes, making them more suitable for various applications, including manufacturing high-performance membranes or mass production of membranes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.620-623
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• 2001

The peculiarities of using Self-propagating High-temperature Synthesis (SHS) and solid state phase synthesis for production of high temperature superconductor materials are discussed. Oxide superconductors with general formula $ReBa_2$$Cu_3$$O_{7-x}$ (Re= Y, Yb, Sm, Nd) have been made with using barium oxide initial powder instead of traditional barium carbonate. X-ray powder diffraction showed a single phase orthorhombic perovskite structure was produced in all reactions. Phenomena observed during the grinding of the reactant mixture are presented. Mechano-chemical activation - as a pretreatment of the reactant mixture - strongly influences the kinetic parameters, the reaction mechanism, and the composition and structure of the final product.

• 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.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.6
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• pp.295-300
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• 2010

Metathetic route for the $MWO_4$ (M=Zn, Co) particles is a simple method of synthesis and a viable alternative method in a short time. $MWO_4$ (M=Zn, Co) particles were synthesized using solid-state metathetic (SSM) method with microwave irradiation. The $MWO_4$ (M=Zn, Co) particles were formed completely at $600^{\circ}C$ for 3 h. The crystallization process, thermal decomposition and morphology of the $MWO_4$(M= Zn, Co) particles were evaluated. The characteristics of the SSM reaction and the formation of a high lattice energy by-product NaCl were discussed.

• Journal of the Korean Ceramic Society
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• v.50 no.4
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• pp.257-262
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• 2013

A biomimetic approach was applied for the chemical deposition of calcium phosphate (CaP) coatings on 3 mole% yttrium-stabilized zirconia [3YSZ] powders. The solid-state reaction of 3YSZ powders with the addition of CaP was investigated for the development of biodegradable zirconia ceramics. The solid-state interaction between the 3YSZ matrix powders and the CaP additives differed from the behavior of commercial zirconia matrix powders. The 3YSZ powders were chemically reacted with precursors for the CaP formation. 3YSZ powders were mixed in an aqueous solution of Ca-P precursors and the CaP was precipitated on the surface of the 3YSZ matrix powders. The CaP-doped YSZ powders were calcined at $1100^{\circ}C$ and shaped powder blocks were then fired at $1600^{\circ}C$ for 2 h. The CaP phase formation was investigated using FE-SEM and XRD analysis.