• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.221-223
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• 1999

In this work, samples were manufactured variously by changing conventional calcining and sintering conditions and we tried the utilization by making the heat treatment time, which is demanded to high-Tc phase formation, much shorter. We found out optimal heat treatment conditions with the analysis on formation process at superconducting phase in term of the change of calcining and sintering time and then, examined X-ray diffraction(XRD) patterns, scanning electron microscope(SEM) measurement and energy dispersive X-ray spectrometer(EDX) of the samples manufactured under heat treatment conditions which we suggest here. As a result, 2223 high-$T_c$, phase of (Bi,Pb)SrCaCuO superconductor starting with ($Bi_l$ xPbx,)$_2$$Sr_2$$Ca_2$$Cu_3$$O_y$, composition was formed from 1 hr sintering sample at temperature nearby melting point and also the completed sample with calcining and sintering time of 9 hr was formed high-$T_c$.low-$T_c$ phase appearing in sight above the critical temperature of liquid $N_2$.

• Journal of the Korean Ceramic Society
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• v.31 no.12
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• pp.1561-1569
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• 1994

Effect of calcining temperature on the sintering behaviors and microwave dielectric properties of BMT[Ba(Mg1/3Ta2/3)O3] ceramics was studied. The calcining temperatures were varied from 80$0^{\circ}C$ to 130$0^{\circ}C$, respectively. It was found that, as calcining temperature lowered below 125$0^{\circ}C$, second phase such as Ba5Ta4O15 phases started to appear in calcined powder with unreacted powders. After sintering, exaggerately grown Ba5TaO3 phase could be found amang the uniform BMT grains in sintered body. Basis on the infiltration experiment, Ba0.05TaO3 phase should be formed by reaction of BMT grain and BaO-MgO eutectic liquid. But increase of calcining temperature above 125$0^{\circ}C$, there was not any second phase or unreated component in calcined powder and sintered body. As result, low calcining temperature led to precipitation of second phase in specimen and resulted decrease of Q value of BMT ceramics.

• Journal of the Korean Ceramic Society
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• v.41 no.2
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• pp.165-169
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• 2004

Microwave dielectric properties and the behavior of low-temperature sintering of $Zn_{1-x}(Li_{1/2}La_{1/2})_xTiO_3$ ($0.01{\leq}x{\leq}0.05$) with 4 wt% $H_3BO_3$ were investigated as a function of $(Li_{1/2}La_{1/2})^{2+}$ content. The sintering temperature of the specimens can be reduced from $1150^{\circ}C$ to $875^{\circ}C$ with the addition of 4 wt% $H_3BO_3$ as a sintering agent. Dielectric constant (K) and Temperature Coefficient of resonant Frequency (TCF) with the substitution of ($(Li_{1/2}La_{1/2})^{2+}$ ion depended on dielectric mixing rule. Quality factor (Qf) depended on density and microstructure. Typically, K of 26.5, Qf of 19,030 GHz and TCF of 7.5 ppm$/^{\circ}C$ were obtained for the specimens with x=0.03 sintered at $875^{\circ}C$ for 3 h.

• Electronic Materials Letters
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• v.14 no.6
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• pp.657-668
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• 2018

Organic-inorganic hybrid lead halide perovskites have been extensively investigated for various optoelectronic applications. Particularly, owing to their ability to form highly crystalline and homogeneous films utilizing low-temperature solution processes (< $150^{\circ}C$), perovskites have become promising photoactive materials for realizing high-performance flexible solar cells. However, the current use of mesoporous $TiO_2$ scaff olds, which require high-temperature sintering processes (> $400^{\circ}C$), has limited the fabrication of perovskite solar cells on flexible substrates. Therefore, the development of a low-temperature processable charge-transporting layer has emerged as an urgent task for achieving flexible perovskite solar cells. This review summarizes the recent progress in low-temperature processable electron- and hole-transporting layer materials, which contribute to improved device performance in flexible perovskite solar cells.

• 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.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.814-815
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• 2006

The removal of oxygen during sintering by carbothermic reduction was studied for steel compacts Fe-Cr-Mo-C and Fe-Mo-C prepared from prealloyed powders. The compacts were prepared by pressing at 600 and 1000 MPa and sintering at 1100 and $1300^{\circ}C$ in vacuum. It showed that for the Cr-Mo steel, deoxidation strongly depends on the sintering temperature, in contrast to the plain Mo steel; at $1300^{\circ}C$ very low oxygen levels were measured with the standard density compact while at high density still significant oxygen is contained. This indicates inhibition of final deoxidation by pore closure, but apparently without adverse effect on the mechanical properties.

• Journal of the Korean Ceramic Society
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• v.41 no.9
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• pp.709-714
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• 2004

The additive of low temperature sintering in Mn-doped PMN-PZT known as high piezoelectric materials was studied in this experiment. B$_2$O$_3$ was used for the additive of low temperature sintering. The effects of sintering temperature in dielectric, and piezoelectric properties were investigated with the amounts of B$_2$O$_3$. Sintered density was increased in comparison with no addition and under 2wt％ B$_2$O$_3$ and lower sintering temperature than 100$0^{\circ}C$. Therefore, in the low sintering temperature, the densification was improved by the addition of the B$_2$O$_3$. However, the sintering density was lower than that of the main composition in the case of the sintered at over 10$50^{\circ}C$. Dielectric constant with the addition of B$_2$O$_3$ was evaluated. The dielectric constant was 1000 2 wt％ of B$_2$O$_3$ and sintered at 100$0^{\circ}C$. Under 2wt％ of B$_2$O$_3$, the electromechanical coupling factor and the piezoelectric constant were not so much decreased. The electromechanical coupling factor and the piezoelectric constant were 50％ and 300(${\times}$10$^{-12}$ C/N) respectively. The mechanical quality factor was increased with B$_2$O$_3$. The mechanical quality factor was 1700 at 0.5wt％ B$_2$O$_3$ and sintered at 110$0^{\circ}C$. Dielectric loss was less than 0.5％ regardless of the amount of B$_2$O$_3$.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.228-228
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• 2013

Dye-Sensitized Solar Cells (DSSCs) have attracted great interests as they offer high energyconversion efficiencies at low cost. For the conventional fabrication of DSSCs, high temperature sintering is required for the construction of interconnect $TiO_2$. However, more simplified process which can be applicable to large-sized solar cells module, is strongly necessary for the commercialization of DSSCs. In this work, we developed novel sintering method using Intense Pulsed Light (IPL), which can replace the conventional high temperature sintering methods. The photovoltaic properties of DSSCs utilizing IPL methods will be reported.

• Journal of the Korean Ceramic Society
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• v.25 no.6
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• pp.623-630
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• 1988

As a function of the composition and content of frit, the electrical property of Ag and Ag/Pd thick film conductors were investigated with microstructure. With increasing sintering temperature in Ag-frit thick film conductors, electrical sheet resistivity decreased, but again increased above 80$0^{\circ}C$. And when frit contents is 5wt%, compact and homogenious microstructure can be obtained, then electrical sheet resistivity has minimum value. In Ag/Pd-frit film conductor, the electrical sheet resistivity decreased with increasing sintering temperature. The system which having frit with low softing point has lower sheet resistivity then to add high softening point frit.

• Electrical & Electronic Materials
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• v.1 no.1
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• pp.26-34
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• 1988

Sintered CdS/CdTe solar cells have been farbricated by coating a (Cd+Te) slurry on sintered CdS films followed by the sintering at 625.deg.C for one hour with various heating rates. When cadmium and tellurinm powders are used instead of CdTe powder to form CdS/CdTe junction, CdTe is formed in the temperature range of 290.deg.C-400.deg.C. The microstructure of the CdTe films depends strongly on the heating rate of the sintering due to the low melting temperature and the high vapor pressure of the elemental Cd and Te. An optimum heating rate obtain CdTe films with uniform and dense microstructure which, in turn, improves the efficiency of the sintered CdS/CdTe solar cells. All-polycrystalline CdS/CdTe solar cells with an efficiency of 9.57% under 50mW/cm$^{2}$ tungsten light have been farbricated by using a heating rate of 14.deg.C/min.