• Journal of the Korean Vacuum Society
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• v.7 no.1
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• pp.51-58
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• 1998

ZnS and TB-doped ZnS (ZnS:Tb) thin films were grown by traveling wave reactor atomic layer epitaxy (AKE) and characterized using materials and surface analysis techniques. $ZnCl_2$, $H_2$S,and tris(2,26,6-tetramethyl-3,5-heptandionato) terbium ($Tb(TMHD)_3$) were used as the precursors in the growth of ZnS:Tb films. The dependence of Cl content in ZnS films on growth temperature was investigated using Rutherford backscattering spectrometry. The Cl content decreased from approximately 9 at.% to 1 at. % as increasing the growth temperature from 400 to $500^{\circ}C$. The segregation of Cl in near surface region was also observed by depth profiling using Auger electron spectroscopy. Scanning electron microscopic studies showed that the ALE-grown ZnS and ZnS:Tb film during ALE process using $Tb(TMHD)_3$was also investigated. Approximately 1 at.% of O in ZnS:Tb(0.5 at.%) film which showed a good crystallinity of hexagonal 2H structure.

• 한국전기화학회:학술대회논문집
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• 2005.07a
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• pp.373-378
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• 2005

[ $Zn(BH_4)_2$ ] ($8.4\;wt\%$ theoretical hydrogen storage capacity) powders have been successfully synthesized by mechanochemical reaction from mixtures of $ZnCl_2$ and $NaBH_4$ powders in a 1:2 molar ratio in different times. $$ZnCl_2\;+\;2NaBH_4\rightarrow\;Zn(BH_4)_2\;+\;2NaCl\;(1)$$ $Zn(BH_4)_2$ powders were characterized by X-ray diffractometry(XRD), and Furier Transform Infrared spectrometry(FT-IR). The thermal stabilities of $Zn(BH_4)_2$ powders were studied by Differential scanning calorimetry(DSC), Thermogravimetry analysis(TGA), and Mass spectrometry(MS). $Zn(BH_4)_2$ can be tested for hydrogen evolution without further purification. The reaction to yield hydrogen is irreversible, the other products being compounds of Zn, and borane. $Zn(BH_4)_2$ thermally decomposes to release borane and hydrogen gas between about 85 and $150^{\circ}C$.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.41-42
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• 2008

본 논문에서는 As-doped ZnO 박막의 플라즈마 식각 특성 및 메커니즘에 관하여 실험을 수행 하였다. As-doped ZnO 박막 식각 실험은 유도 결합 플라즈마 식각 장비(inductively coupled plasma;ICP)와 $BCl_3$/Ar 플라즈마에 첨가된 $Cl_2$가스의 비, RF 전력, DC bias voltage, 공정 압력에 대한 식각 속도의 변화를 관찰 하였다. $BCl_3$/Ar 플라즈마에 $Cl_2$ 가스 첨가량 6 sccm 까지는 증가하지만 그 이후 $Cl_2$ 가스의 첨가량이 증가할 때 식각속도가 감소하였다. 이는 플라즈마 내에서 Cl 라디칼의 밀도가 증가함에 따라서 $Ar^+$의 에너지가 감소와 비휘발성 식각 부산물의 증가에 의하여 효과적인 물리적 식각이 이루어 지지 못한 것으로 판단된다. OES를 이용하여 플라즈마 내에서 라디칼들의 빛의 세기를 측정하였고, 식각 후 As-type ZnO 박막 표면에서의 화학적 결합을 보기위해 XPS 분석을 실행하였다.

• Transactions on Electrical and Electronic Materials
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• v.12 no.2
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• pp.60-63
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• 2011

We investigated the etching characteristics of zinc oxide (ZnO) and the effect of additive gases in a $Cl_2$-based inductively coupled plasma. The inert gases were argon, nitrogen, and helium. The maximum etch rates were 44.3, 39.9, and 37.9 nm/min for $Cl_2$(75%)/Ar(25%), $Cl_2$(50%)/$N_2$(50%), and $Cl_2$(75%)/He(25%) gas mixtures, 600 W radiofrequency power, 150 W bias power, and 2 Pa process pressure. We obtained the maximum etch rate by a combination of chemical reaction and physical bombardment. A volatile compound of Zn-Cl. achieved the chemical reaction on the surface of the ZnO thin films. The physical etching was performed by inert gas ion bombardment that broke the Zn-O bonds. The highly oriented (002) peak was determined on samples, and the (013) peak of $Zn_2SiO_4$ was observed in the ZnO thin film sample based on x-ray diffraction spectroscopy patterns. In addition, the sample of $Cl_2$/He chemistry showed a high full-width at half-maximum value. The root-mean-square roughness of ZnO thin films decreased to 1.33 nm from 5.88 nm at $Cl_2$(50%)/$N_2$(50%) plasma chemistry.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.05a
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• pp.225-231
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• 2006

.고상반응법 (solid state reaction)합성된 ZnS:Mn,Cu,Cl 형광체는 약 $20^{\sim}25{\mu}m$ 의 구형이고, Cubic/hexagonal 구조를 보였다. Electroluminescent device(ELD)는 실크 스크린된 형광층(ZnS:Mn,Cu,Cl)/유전체층 ($BaTiO_3$)으로 구성되었으며, 각층은 $30^{\sim}50{\mu}m,\;50^{\sim}60{\mu}m$ 정도로 도포 하였다. 100 V-400 Hz 의 구동조건에서, ELD 의 백색 발광은 450 nm, 480 nm 픽에서 각각 $Cl_s{\to}Cu^{+}\;_{Zn},\;Cl_s{\to}Cu^{2+}\;_{Zn}$ 전이에 의해 중첩된 청색, 녹색 밴드의 발광과, 580 nm 픽에서 Mn 의 $^{4}T_1{\to}^{6}A_1$ 전이에 의한 황색 밴드의 발광으로 이루어진다. Cu 농도의 증가에 따라 450 nm 의 발광 밴드의 휘도는 감소하며 580 nm 의 발광 밴드의 휘도가 증가하였고 발광 휘도가 향상되었다. 즉, 색온도가 높은 cold white(10000 K)에서 색온도가 낮은 Warm white(3000 K) 로 변한다. 이것은 450 nm 의 발광 밴드가 580 nm 의 발광 밴드에 흡수되는 에너지 전이 (Energy transfer) 현상에 기인한다. ZnS:Mn,Cu,Cl 의 Mn 1.5 wt %, Cu 2.5 wt.% 에서 최적 발광 휘도를 보이며, 100 V-400 Hz 에서 약 $12cd/cm^2$이였다.

• Journal of Environmental Health Sciences
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• v.27 no.2
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• pp.82-91
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• 2001

This study was carried out to elucidate the protective effect of zinc chloride(ZnCl$_2$) and its mechanism against the immuno-cytotoxicity of methylmercury chloide($CH_3$HgCl). This study was observed in the culture of EMT-6 cells which are originated from mammary adenocarcinoma of Balb/c mouse. Cytotoxicity of metals was measured by cell viability and NO$_2$$^{[-10]}$ , and mitochondrial function was evaluated by adenosine triphosohate (ATP) production. $CH_3$HgCl significantly decreased the sythesis of nitric oxide(NO), ATP and glutathione(GSH) in a dose-dependent manner. ZnCl$_2$ significantly increased the synthesis of GSH in a dose-dependent manner, but synthesis of NO and ATP were not changed. The immuno-cytotoxicity of $CH_3$HgCl was not fully protected when combined addition of ZnCl$_2$, whereas ZnCl$_2$ prior to addition of $CH_3$HgCl completly protected the Hg-induced immuno-cytotoxicity. Similarly, intracellular accumulation of mercury significantly decreased by ZnCl$_2$. Degree of diminution of intracellular mercury was larger in ZnCl$_2$ prior to addition of $CH_3$HgCl than in combined addition of ZnCl$_2$ and $CH_3$HgCl.. Dithiothreitol(DTT) or buthionine sulfoximine(BSO) addition at 50$\mu$M or less, which was not toxic to the cells, did not affect synthesis of NO and ATP. DTT increased intracellular GSH level and DTT pretreatment protected toxicity induced by $CH_3$HgCl as shown complete recover in the NO and ATP values. BSO decreased intracellular GSH level and BSO pretreatment exaggerated toxicity induced by $CH_3$HgCl as shown synergistic reduction in the NO and ATP values. These results indicated that the protective effects of zinc against immuno-cytotoxicity of methylmercury associated with increasing cellular level of GSH. Increased intracellular GSH transports methylmercury to out of cells. In accordance with intracellular level of mercury decreased, immuno-cytotoxicity of methylmercury decreased. These result also suggest that the protective mechanism of zinc against the mercury toxicity would be exerted in the immune system in vivo.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1043-1044
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• 2006

Compositional dependence of corrosion behavior of rapidly solidified Mg-rich Mg-Zn-Y alloys in NaCl aqueous solution has been investigated. Mg-Zn-Y ternary alloys containing small amounts of Zn exhibited low corrosion rate, although the $Mg_{98}Y_2$ (at. %) binary alloy showed severe corrosion with violet evolution of hydrogen. The alloy with highest corrosion-resistance was $Mg_{97.25}Zn_{0.75_Y_2$, its corrosion rate was about 1 mm year-1 in 0.17 M (1.0 wt. %) NaCl solution. $Mg_{97.25}Zn_{0.75}Y_2$ alloy exhibited passive region in anodic polarization curves when immersed in NaCl solution. Rapidly solidification and small amount of Zn addition may bring about an increase in electrochemical homogeneity of Mg-Zn-Y alloys, resulting in enhancement of corrosion resistance.

• Journal of Environmental Science International
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• v.16 no.9
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• pp.1091-1098
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• 2007

Activated carbon was prepared from waste citrus peels by chemical activation with $ZnCl_2$. The optimal condition of carbonization was at $300^{\circ}C$ for 1.5 hr. Activation experiments with carbonized samples prepared at optimal carboniztion condition were carried out under various conditions such as activation temperature of 400 to $900^{\circ}C$, activation time of 0.5 to 2.0 hr, and $ZnCl_2$ ratio of 100 to 300%. In order to investigate the physical properties of the activated carbons prepared, iodine adsorptivities and specific surface areas were measured and their morphologies were observed from scanning electron microscopy. As $ZnCl_2$ ratio increased, activation yield decreased, while iodine adsorptivity and specific surface area increased. The optimal condition of activation was at 300% $ZnCl_2$ ratio and $300^{\circ}C$ for 1.5 hr, and then iodine adsorptivity and specific surface area was measured as about 862 mg/g and $756m^2/g$, respectively. SEM photography showed that the surface morphology was changed and many active pore were produced by chemical activation.

• Journal of the Korean Ceramic Society
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• v.30 no.1
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• pp.25-33
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• 1993

Formation reaction of Mn-Zn ferrite depending on various synthetic conditions of wet process was investigated using FeCl2.nH2O(n≒4), MnCl2.4H2O, ZnCl2 as starting materials. A stable intermediate precipitate was formed by the addition of H2O2. And the precipitate was hard to transform to spinel phase of Mn-Zn Fe2O4. Single phase of Mn-Zn Fe2O4 spinel was obtained above 8$0^{\circ}C$ reaction temperature. The powder had spherical particle shape and 0.02~0.05${\mu}{\textrm}{m}$ particle size. Fe(OH)2 solid solution, -FeO(OH) solid solution, -FeOOH, Mn-Zn Fe2O4 spinel were formed with air flow rate 180$\ell$/hr. However, single phase of Mn-Zn Fe2O4 spinel with cubic particle shape and 0.1~0.2${\mu}{\textrm}{m}$ particle size was formed with synthetic conditions of 8$0^{\circ}C$ and 90 munutes. The particle shape of the -FeOOH was needle-like.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.05a
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• pp.35-37
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• 1988

Polycrystalline $Cd_{1-x}Zn_xS$ films were prepared by coaling a slurry which consisted of CdS, ZnS, $CdCl_2$ and propylene glycol on gloss substrates and by sintering in a nitrogen atmosphere. Microstructures, optical transmittance and electrical resistance of the sintered films have been investigatd. Grain shape of $Cd_{1-x}Zn_xS$ films sintered in a sealed boat was nearly spherical but the shape became, irregular when sintered in evaporating condition due to occurrence of CIGM (Chemically Induced Grain-boundary Migration). Controlling the rate of evaporation of $CdCl_2$, sintered $Cd_{1-x}Zn_xS$ films with high optical transmittance and low electrical resistance could be obtained.