• Title/Summary/Keyword: Zn concentration

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Surface morphology, Glossiness and Hardness of Zn-Cr and Zn-Cr-X ternary alloy Electrodeposits (고속도금된 Zn-Cr 및 Zn-Cr-X 3원합금 도금층의 표면조직, 광택도 및 경도)

  • 예길촌;김대영;서경훈
    • Journal of the Korean institute of surface engineering
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    • v.36 no.5
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    • pp.379-385
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    • 2003
  • The surface morphology, the glossiness and the hardness of Zn-Cr and Zn-Cr-X(X:Co, Mn) alloy electrodeposits were investigated by using chloride bath with EDTA additive and flow cell system. The surface morphology of Zn-Cr alloy and Zn-Cr-Mn alloy changed from fine needle shape crystalline structure to colony structure of fine granular crystallites with increasing current density in the range of 20-100 $A/dm^2$. The surface morphology of Zn-Cr-Co alloy deposited from low Co concentration bath(2.5-10 g/$\ell$) was similar to that of Zn-Cr alloy, while that of Zn-Cr-Co alloy deposited from high cobalt concentration bath was fine granular crystalline structure in the same range of current density. The glossiness of Zn-Cr and Zn-Cr-Mn alloy increased noticeably with increasing current density, while that of Zn-Cr-Mn alloy decreased with increasing Mn concentration of bath in high current density region. The glossiness of Zn-Cr-Co alloy deposited from low Co concentration bath increased with current density while that of the alloy from high Co concentration bath decreased with increasing current density. The hardness of Zn-Cr and Zn-Cr-X alloy increased noticeably with current density.

Structural, Optical and Electrical Properties of ZnO Thin Films with Zn Concentration (Zn 농도변화에 따른 ZnO 박막의 구조, 광학 및 전기적 특성 연구)

  • 한호철;김익주;태원필;김진규;심문식;서수정;김용성
    • Journal of the Korean Ceramic Society
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    • v.40 no.11
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    • pp.1113-1119
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    • 2003
  • We used isopropanol which has low boiling point to prepare thin films at low temperature and changed mole concentration of zinc acetate from 0.3 to 1.3 mol/l. The structural, optical and electrical properties of ZnO thin films with Zn content were investigated. ZnO thin films highly oriented along the c-axis were obtained at Zn concentration of 0.7 mol/l. ZnO thin films with Zn concentration of 0.7 mol/l showed a homogeneous surface layer of nano structure. The transmittance of ZnO thin films by UV-vis. measurement was about 87% under the Zn concentration of 0.7 mol/l, but rapidly decreased over the 1.0 mol/l. The optical band gap energy was obtained from 3.07 to 3.22 eV which is very close to the band gap of bulk ZnO (3.2 eV). The electrical resistivity of ZnO thin films was about 150 $\Omega$-cm that shows little difference with Zn concentration. I-V curves of ZnO thin films exhibited typical ohmic contact properties.

열수화법으로 성장시 성장 온도에 따른 ZnO 나노 구조의 표면 형상 변화

  • Bae, Yeong-Suk;Kim, Dong-Chan;Jo, Hyeong-Gyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.238-238
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    • 2009
  • In this work, we investigated the effect of the Zn complex concentration and growth temperature on the growth of ZnO nanorod by hydrothermal method. The ZnO nanorods were performed at condition of the various Zn complex concentration and growth temperature, 0.02 ~ 0.08 M and 60 ~ 80 $^{\circ}C$, respectably. We found from the SEM results that the diameter and length of ZnO nanorods were with increasing the growth temperature and Zn complex concentration. However, the growth condition in the two parameters wasmore than sensitive compared to Zn complex concentration on increasing the growth rate. From photoluminescence(PL) analysis, the strong band-edge emission for ZnO nanorod grown at 80 $^{\circ}C$ with 0.08 M indicated the fine crystallinity. Therefore, the diameter and length of ZnO nanorods have been able to control through the control of front growth parameters. Also, these ZnO nanorods grown low temperature will be available as building block for transparence flexible device applications.

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Characterization of Zn diffusion in TnP Cy $Zn_3P_2$ thin film and rapid thermal annealing (RHP에서의 $Zn_3P_2$ 박막 및 RTA법에 의한 Zn 확산의 특성)

  • 우용득
    • Journal of the Korean Vacuum Society
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    • v.13 no.3
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    • pp.109-113
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    • 2004
  • Zn diffusions in InP have been studied by electrochemical capacitance voltage. The InP layer was grown by metal organic chemical vapor deposition, and $Zn_3P_2$ thin film was deposited on the epitaxial substrates. The samples annealed in a rapid thermal annealing. It is demonstrated that surface hole concentration as high as $1\times10^{19}\textrm{cm}^{-3}$ can be achieved. When the Zn diffusion was carried at $550^{\circ}C$ and 5-20 min., the diffusion depth of hole concentration moves from 1.51$\mu\textrm{m}$ to 3.23 $\mu\textrm{m}$, and the diffusion coeffcient of Zn is $5.4\times10^{-11}\textrm{cm}^2$/sec. After activation, the concentration is two orders higher than that of untreated sample at 0.30 $\mu\textrm{m}$ depth. As the annealing time is increase, the hole concentration remains almost constant, except deep depth. It means that excess Zn interstitials exist in the doped region is rapidly diffusion into the undoped region and convert into substitutional When the thickness of $SiO_2$ thin film is above 1,000$\AA$, the hole concentration becomes stable distribution.

Effect of Several Zinc Solutions on Concentration of Oral Volatile Sulfur Compounds(VSCs) (수종의 Zinc 수용액이 구강내 휘발성 황화합물의 농도에 미치는 영향)

  • Park, Moon-Soo;Han, Song
    • Journal of Oral Medicine and Pain
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    • v.25 no.1
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    • pp.1-7
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    • 2000
  • The purpose of this study is to investigate effects of several zinc solutions including Artemisia asiatica-containing zinc solution on concentration of oral volatile sulfur compounds(VSCs). We determined the VSCs concentration of breath of human subjects before and after use of zinc solutions(O.25% $ZnF_2$ Artemisia asiatica-containing 0.25% $ZnCl_2$ and Artemisia asiatica-containing 0.25% $ZnCl_2$ solutions) The results were as follows : 1. 0.25% $ZnCl_2$ solution was more effective than 0.25% $ZnF_2$ solution in reducing the concentration of oral VSCs and the maintenance duration of effectiveness. 2. Artemisia asiatica-containing 0.25% $ZnCl_2$ solution was more effective than Artemisia asiatica-containing 0.25% $ZnF_2$ solution in reducing the concentration of oral VSCs and the maintenance duration of effectiveness. 3. Artemisia asiatica-containing 0.25% $ZnF_2$ solution and 0.25% $ZnF_2$ solution showed no significant difference in reducing the concentration of oral VSCs and the maintenance duration of effectiveness but, Artemisia asiatica-containing 0.25% $ZnF_2$ solution was slightly more effective. 4. Artemisia asiatica-containing 0.25% $ZnCl_2$ solution and 0.25% $ZnCl_2$ solution showed no significant difference in reducing the concentration of oral VSCs and the maintenance duration of effectiveness but, Artemisia asiatica-containing 0.25% $ZnF_2$ solution was slightly more effective.

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Cadmium and zinc interaction and phytoremediation potential of seven Salix caprea clones

  • Han, Sim-Hee;Kim, Du-Hyun;Lee, Jae-Cheon
    • Journal of Ecology and Environment
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    • v.33 no.3
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    • pp.245-251
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    • 2010
  • We evaluated the interaction between Cd and Zn in the bioaccumulation of seven clones of Salix caprea, which were exposed both to Cd and Zn alone and to a combination of Cd and Zn. Cadmium (Cd) and Zn concentration in the four treatments were administered in the following order: root > leaf > stem, and obvious differences were noted among the treatments and clones. The leaf Cd concentration of clone BH2 and stem Cd concentration of clone BH5 in the combined Cd and Zn treatment group was increased by 62% and 110%, respectively, relative of that of the Cd alone treatment group. On the other hand, the leaf and stem Zn concentration of clone BH8 in the combined Cd and Zn treatment group was reduced by 66% and 61%, respectively, relative to that of the Zn alone treatment group. Translocation of Cd and Zn from the root was higher in the leaf than in the stem, and the combined Cd and Zn treatment stimulated the translocation of Cd from the root to the leaf and stem, whereas it suppressed the translocation of Zn from the root to the leaf and stem. Therefore, the interaction effects were considered strongly synergistic with Cd in the presence of Zn, but proved antagonistic to Zn in the presence of Cd in the combined Cd and Zn treatment group. The phytoremediation potentials of the seven clones, which were estimated from standard indices of Cd and Zn concentration in Cd and Zn alone and the combined Cd and Zn treatment groups, were highest in clone BH3, and lowest in clone BH5. Therefore, we recognize S. caprea as an appropriate material for phytoremediation, and this is particularly the case with clone BH3. However, further research will be required to evaluate the effects of Cd and Zn on the physiological changes as well as tolerance mechanisms against metal toxicity in S. caprea clones.

Annealing Effect of Phosphorus-Doped ZnO Nanorods Synthesized by Hydrothermal Method (Phosphorus-Doped ZnO 나노로드의 열처리 효과)

  • Hwang, Sung-Hwan;Moon, Kyeong-Ju;Lee, Tae Il;Myoung, Jae Min
    • Korean Journal of Materials Research
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    • v.23 no.5
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    • pp.255-259
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    • 2013
  • An effect of thermal annealing on activating phosphorus (P) atoms in ZnO nanorods (NR) grown using a hydrothermal process was investigated. $NH_4H_2PO_4$ used as a dopant source reacted with $Zn^{2+}$ ions and $Zn_3(PO_4)_2$ sediment was produced in the solution. The fact that most of the input P elements are concentrated in the $Zn_3(PO_4)_2$ sediment was confirmed using an energy dispersive spectrometer (EDS). After the hydrothermal process, ZnO NRs were synthesized and their PL peaks were exhibited at 405 and 500 nm because P atoms diffused to the ZnO crystal from the $Zn_3(PO_4)_2$ particles. The solubility of the $Zn_3(PO_4)_2$ initially formed sediment varied with the concentration of $NH_4OH$. Before annealing, both the structural and the optical properties of the P-doped ZnO NR were changed by the variation of P doping concentration, which affected the ZnO lattice parameters. At low doping concentration of phosphorus in ZnO crystal, it was determined that a phosphorus atom substituted for a Zn site and interacted with two $V_{Zn}$, resulting in a $P_{Zn}-2V_{Zn}$ complex, which is responsible for p-type conduction. After annealing, a shift of the PL peak was found to have occurred due to the unstable P doping state at high concentration of P, whereas at low concentration there was little shift of PL peak due to the stable P doping state.

Application of Reverse Osmosis Plate and Frame Type for Separation and Concentration Heavy Metal[Cu(II), Zn(II)] (중금속[Cu(II), Zn(II)]의 분리 및 농축을 위한 역삼투 판틀형 모듈의 적용)

  • Lee, Kwang-Hyun;Kang, Byung-Chul;Lee, Jong-Baek;Kim, Jong-Pal
    • Journal of Korean Society on Water Environment
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    • v.20 no.4
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    • pp.307-312
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    • 2004
  • This study was focused on experiment for the separation and concentration process of Cu(II), Zn(II) solution with the variation of applied pressure and concentration using reverse osmosis plate and frame modules. Rejection coefficient and degree of concentration for Cu(II) component using single and multi-stage reverse osmosis process were showed 96.3~97.8%, 0.044~0.191(in single-stage), 96.3~98.4%, 0.400~2.264(in multi-stage) within the range of experimental condition, respectively. Those of Zn(II) were 93.3~97.1%, 0.019~0.395(in single-stage), 96.3~98.2%, 0.365~1.454(in multi-stage), respectively. Degree of concentration of multi-stage were higher than those of single-stage. Heavy metal[Cu(II), Zn(II)] separation was very efficient in using reverse osmosis plate and frame type modules. Separation efficiency for a mixed solution Cu(II) and Zn(II) was higher than those of each one of Cu(II) and Zn(II).

Effective Oxygen-Defect Passivation in ZnO Thin Films Prepared by Atomic Layer Deposition Using Hydrogen Peroxide

  • Wang, Yue;Kang, Kyung-Mun;Kim, Minjae;Park, Hyung-Ho
    • Journal of the Korean Ceramic Society
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    • v.56 no.3
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    • pp.302-307
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    • 2019
  • The intrinsic oxygen-vacancy defects in ZnO have prevented the preparation of p-type ZnO with high carrier concentration. Therefore, in this work, the effect of the concentration of H2O2 (used as an oxygen source) on the oxygen-vacancy concentration in ZnO prepared by atomic layer deposition was investigated. The results indicated that the oxygen-vacancy concentration in the ZnO film decreased by the oxygen-rich growth conditions when using H2O2 as the oxygen precursor instead of a conventional oxygen source such as H2O. The suppression of oxygen vacancies decreased the carrier concentration and increased the resistivity. Moreover, the growth orientation changed to the (002) plane, from the combined (100) and (002) planes, with the increase in H2O2 concentration. The passivation of oxygen-vacancy defects in ZnO can contribute to the preparation of p-type ZnO.

Control of electron concentration and photoluminescence intensity of ZnO thin films using oxygen gas (산소 가스를 이용한 산화아연의 전자 농도와 광발광 세기 조절)

  • Kang, Hong-Seong;Kim, Jae-Won;Lee, Sang-Yeol
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.185-187
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    • 2004
  • The electron concentration of ZnO thin film fabricated by pulsed laser deposition was controlled by varying oxygen gas pressure. The electron concentration of ZnO was increased from $10^{17}\;to\;10^{19}/cm^3$ as oxygen gas pressure increased from 20 mTorr to 350 mTorr. Ultraviolet(UV) intensity of photoluminescence of ZnO was controlled, too. UV intensity of ZnO was increased as oxygen gas pressure increased from 20 mTorr to 350 mTorr. The relation between electron concentration and UV intensity was investigated.

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