• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.524-526
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• 2009

The effects of In and Ga contents on characteristics of InGaZnO (IGZO) films grown by a sol-gel method and their thin film transistors (TFTs) have been investigated. Excess In incorporation into IGZO enhances the field effect mobilities of the TFTs due to the increase in conducting path ways, and decreases the grain size and the surface roughness of the films because more $InO_2^-$ ions induce cubic stacking faults with IGZO. Ga incorporation into results in decrease in carrier concentration of films and off-current of TFTs since Ga ion forms stronger chemical bonds with oxygen than Zn and In ions, acting as a carrier killer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.374-378
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• 1999

Thin Films of BaYTiO system were Prepared by frequency (rf)/dc magnetron sputtering method. The preparation of target were accomplished by the mixed oxide method, and their composition consisted of the $Ba_{0.997}$ $Y_{0.003}$Ti $O_3$+0.5 $SiO_2$+x $M_{n}$O(x=0, 0.073, 0.1, 0.127, 0.154). The average particle size of (Ba,Y)Ti $O_2$ system ceramics with Mn $O_2$ additives increases as the amount of MnO additives increase and reaches the maximum grain growth when the amount of MnO is 0.127(mol%).).).).

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1643-1645
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• 2000

The effects of pre-sintering and infiltration conditions on the electrical and physical properties of Cu-Cr contact material have been studied. Specimens were prepared by infiltration technique, aiming at the final composition of Cu50w%Cr, with varying pre-sintering and infiltration conditions. It showed that increased pre-sintering temperature had a little influence on the final microstructure of Cu-Cr contact material, but improved the surface morphology of Cr-skeleton resulting in better wettability in the followed infiltration process. It also showed that Cr grain growth and gram shape change became prominent with increasing infiltration temperature and time.

• Journal of Ocean Engineering and Technology
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• v.11 no.3
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• pp.39-47
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• 1997

Recently developed TMCP steels, which were manufactured by controlled rolling followed by accelerated cooling process, were examined to study their characteristics and weldability. Accelerated cooling type TMCP steel's hardness test result exhibited high value on weld zone. On the contrary, base metal and HAZ exhibited comparatively the similar value. On this experiment result Softening of HAZ is not occurred. in the-heat affected zone, grain size repression be caused by chemical composition properties which a small quantity Al-Ti-B-N. Changing stress ratio near-threshold fatigue crack propagation experiments were carried out. According to this result, crack propagation velocity of the HAZ exhibited slower than the base metal and near-threshold value had increased at the HAZ. Finally accelerated cooling type TMCP steels were exhibited excellent mechanical properties in both strength and toughness.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.442-445
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• 2001

In this study, microstructural and dielectric properties of P $b_{0.83}$(L $a_{0.2}$C $e_{0.8}$)$_{0.08}$Ti $O_3$PCT ceramics as a function of Mn $O_2$ addition were investigated for 30MHz ceramic resonator application. Grain size was gradually increased according to the increase of Mn $O_2$ addition amount and showed the highest value of 1.502${\mu}{\textrm}{m}$ at the 0.9wt% Mn $O_2$. Moreover, density showed the highest value of 7.582 g/$\textrm{cm}^2$ at the 0.7wt% Mn $O_2$. All the composition ceramics, curie temperature was nearly constant around 33$0^{\circ}C$.EX>.>.>.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.64-66
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• 2004

$Pb(Zr_{0.3},Ti_{0.7})O_3$, $Pb(Zr_{0.3},Ti_{0.3})O_3$ powders were prepared by the sol-gel method and PZT heterolayered thick films were fabricated by the screen-printing method. The structural properties as a faction of the composition ration were studied. As a result of the differential thermal analysis (DTA), exothermic peak was observed at around $864^{\circ}C$ dne to the formation of the polycrystalline perovskite phase. The PZT heterolayered thick film sintered at $1050^{\circ}C$ for 10min showed the average grain size $1{\sim}1.4{\mu}m$. The average thickness of PZT heterolayered thick films, obained by $3{\sim}6times$ of screen-printing, was approximately $60{\sim}110{\mu}m$.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.536-537
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• 2006

In the present work, the sintering behavior of high strength Al-5.6Zn-2.5Mg-1.6Cu (in wt.%) alloy compacts prepared from elemental powders was investigated. Microstructural evaluation was accompanied by XRD and DSC methods in order to determine the temperature and chemical composition of the liquid phases formed during sintering. It was found that three transient liquid phases are formed at 420, 439 and 450 $^{\circ}C$. Microstructural study revealed the progressive formation of sintered contacts due to the presence of the liquid phases, although the green compact expands as a result of the melt penetration along the grain boundaries. While Zn melts at ${\sim}420\;^{\circ}C$, the intermetallic phases formed between Al and Mg were found to be responsible for the formation of liquid phase and the dimensional change at higher temperatures.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.1
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• pp.51-59
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• 2005

The settling rate of the dredged soil may vary with mineral composition, grain size distribution, initial con contration and salt concentration of suspension of the site. A series of settling column test was performed to investigate the settling rate characteristics of solid suspension material from dredging and reclamation. The settling rate of soil mixed with various size of particles depended on clay fraction which showed a inherent flux. A model was developed to predict the particle flux of mixed soil from the clay flux and its applicability was verified.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.246-247
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• 2007

(Ba,Sr,Ca)$TiO_3$ powders, which were prepared by sol-gel method using a solution of Ba-acetate, Sr-acetate and Ca-acetate and Ti iso-propoxide, were mixed with organic vehicle and the BSCT thick films were fabricated by the screen-printing techniques on high purity alumina substrates. The structural and dielectric properties were investigated for various $Dy_2O_3$ doping contents. As a result of thermal analysis, the exothermic peak was observed at around $670^{\circ}C$ due to the formation of the polycrystalline perovskite phase. All BSCT thick films, sintered at $1420^{\circ}C$ for 2h, showed the typical XRD patterns of perovskite polycrystalline structure and no pyrochlore phase was observed. The average grain size of the specimens decreased with.

• Journal of the Korean institute of surface engineering
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• v.25 no.3
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• pp.133-143
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• 1992

Titanium nitride(TiN) films have been prepared by HCD plasma enhanced reactive ion plating. Density and temperature of the plasma generated by the HCD were investigated. It was shown that parameters such as the substrate bias voltage(0 350V) and N2 flow rate(10 180SCCM) influenced the growth, the growth, the microstructure and the color tone of the film mostly. In order to study the interface region, surface analysis by AES combined with sputter depth profiling was performed. Microhardness of the coated TiN films were measured by micro Vickers hardness tester. Also, the effect of coating parameters on composition, coating surface and fracture morphology, grain size and growth rate were examined.