• Title/Summary/Keyword: Oxidized layer

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Development of Glue for Artifact Conservation Using Papermaking Starch (Part 1) - The Nature and Adhesive Strength of Glues - (제지용 전분을 이용한 문화재 보존용 기능성 풀 개발 (제1보) - 풀의 종류에 따른 접착 특성 -)

  • Yi, Sun-Jo;Choi, Tae-Ho
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.46 no.4
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    • pp.44-53
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    • 2014
  • This research were aimed at developing starches which have high preservability and high bonding strength from corn starch, modified cationic and oxidized corn starches, as compared to the fermented wheat starch. On the lining that attaching the base paper on the back of the work with paste, the coating weight was determined by the solid contents of the paste rather than the viscosity of paste. Adhesive strength and stiffness were also determined by the solid contents of the paste. Corn starch had lower solid contents, higher viscosity, and higher adhesive strength than other starches. In the iodine stain to the surface of peeled base paper off, paste deeply penetrated into the traditional Hanji than modern Hanji. And oxidized starch paste deeply penetrated into the paper layer than the cationic starch.

Effect of the Coating on the Structure and Optical Properties of GaN Nanowires

  • Lee, Jong-Soo;Sim, Sung-Kyu;Min, Byung-Don;Cho, Kyoung-Ah;Kim, Hyun-Suk;Kim, Sang-Sig
    • Transactions on Electrical and Electronic Materials
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    • v.5 no.3
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    • pp.113-119
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    • 2004
  • Structural and optical properties of as-synthesized, Ga$_2$O$_3$-coated, and Al$_2$O$_3$-coated GaN nanowires are examined in this paper. GaN nanowires were synthesized by thermal evaporation of ball-milled GaN powders in an NH$_3$ atmosphere. The thermal annealing of the as-synthesized GaN nanowires in an argon atmosphere allows their surfaces to be oxidized, leading to the formation of 2nm-thick Ga$_2$O$_3$ layers. For the oxidized GaN nanowires, the distances between the neighboring lattice planes are shortened, and an excitonic emission band is remarkably enhanced in intensity, compared with the as-synthesized GaN nanowires. In addition, the as-synthesized GaN nanowires were coated cylindrically with Al$_2$O$_3$ by atomic layer deposition technique. Our study suggests that the Al$_2$O$_3$-coating passivates some of surface states in the GaN nanowires.

$Ga_2O_3$ synthesis using GaN mono-crystal powder and its structural properties (GaN 단결정 분말을 이용한 $Ga_2O_3$ 합성 및 구조 특성)

  • Pang, Jin-Hyun;Ko, Jung-Eun;So, Dae-Young;Kim, Young-Soo;Kim, Chong-Don
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.12-13
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    • 2006
  • $Ga_2O_3$ is associated with the fabrication of thin window layer of solar cell. Usually, $Ga_2O_3$ is synthesized from Ga-metal oxidation method and GaN mono-crystal heat treatment method. We synthesized $Ga_2O_3$ powder using two methods and analyzed powder using latter method compared with powder by former method. XPS, XRD, IR analysis are conducted. XPS result, surface of GaN powder is almost oxidized to $Ga_2O_3$ at $1124^{\circ}C$ heat treatment and XRD and IR result, the inside of GaN powder is dramatically oxidized at $1124^{\circ}C{\sim}1300^{\circ}C$.

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Studies on Utilization of Diaminododecane by Microbacterium sp. EL-0112 L (Microbacterium sp. EL - 0112L의 Diaminododecane 자화에 관한 연구)

  • 이미연;이상준
    • Journal of Environmental Health Sciences
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    • v.11 no.2
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    • pp.65-75
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    • 1985
  • Microorganisms capable of utilizing diaminododecane containing amine groups diterminally were isolated from the soil by enrichment culture. One strain of these isolated strain, designated as EL-0112L, was selected for this study. The results of this study were as follows. 1. This isolated strain EL-0112L was identified as Microbacterium, from the results of morphological, cultural, and biochemical tests. This isolated strain was named temporarily Microbacterium sp. EL-0112L for convenience. 2. Microbacterium sp. EL-0112L was tested for ability to utilize different kinds of substitued alkanes containing cyan, amine, chloro, and thiol groups(monoterminally or diterminall substituted) as carbon source. Pentamethylenediamine, hexamethylenediamine, n-decane, laurylamine, and alkane derivatives containing cyan, chloro, and thiol groups were not utilized by Microbacterium sp. EL-0112L. 3. The alkane derivatives that did not serve as growth substrates were tested further in oxidation tests using resting cell preparation of Microbacterium sp. EL-0112 L. Alkane derivatives containing cyan, chloro, thiol groups, and n-decane were oxidized by Microbacterium sp. EL-0112 L. It is possible that this isolated strain is also able to degrade their substituted counterparts since they are structually similar to diaminododecane. The remarkable substrates that were being oxidized were dichlorodecane, and 1-dodecanethiol. Microbacterium sp. EL- 0112L could not oxidize pentamethylenediamine, and hexamethylenediamine. 4. The metabolic products formed from diaminododecane by Microbacterium sp. EL-0112 L were acid compound containing carboxyl group and not containing amine group. On the thin layer chromatography, Rf values of these metabolic products were different from that of the product formed by Corynebacterium sp. EL-0112L. These results suggested the specificity of diaminododecane as carbon source.

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Effect of Al Alloy Composition on Physical and Crystallographical Properties of Plasma Electrolytic Oxidized Coatings II. Crystallographic Analysis of PEO Layer (플라즈마 전해 산화 코팅에 있어서 알루미늄 합금 모재 성분의 물리적, 결정학적 영향 II. PEO 층의 결정상 분석)

  • Kim, Bae-Yeon;Lee, Deuk-Yong;Shin, Min-Chul;Shin, Hyun-Gyoo;Kim, Byeong-Kon;Kim, Sung-Youp;Kim, Kwang-Youp
    • Journal of the Korean Ceramic Society
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    • v.47 no.4
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    • pp.283-289
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    • 2010
  • Physical properties of Plasma electrolytic oxidized 8 different kinds of Al alloys, A-1100, A-2024, A-5052, A-6061, A-6063, A-7075, ACD-7B and ACD-12 were investigated. The electrolyte for PEO was $Na_2SiO_3$ and NaOH and some alkali earthen metal salts system solution. $\eta$-alumina, as well as $\gamma$-alumina, was main crystal phase, which were ever reported. Also, $Al_{4.95}Si_{1.05}O_{9.52}$ was found only in this research. So we can conclude that the process conditions of PEO apparatus and composition and concentration of its electrolyte affects crystal structure and physical properties of PEO layers much more than the compositions of Al alloy.

The Electromagnetic Properties in Uncoupled funnel-junction with Various Cr Seed Layer (비결합형 터널접합구조에서 Cr 하지층에 따른 전자기적 특성변화)

  • Park, J.W.;Jeon, D.M.;Yoon, S.Y.;Lee, J.Y.;Suh, S.J.
    • Journal of the Korean Magnetics Society
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    • v.13 no.3
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    • pp.91-96
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    • 2003
  • Cross-geometrical Cr/Co/Al-Ox/Co/Ni-Fe tunnel junctions were fabricated by magnetron sputtering. To form an insulating layer, The Al layer was oxidized in an atmosphere of oxygen-argon mixture at low power after deposition. To enhance the coercivity of the bottom Co layer, The Cr seed layer was deposited on the glass and it led to increase in coercivity. The coercivity increase is due to the increase of roughness through the Cr thickness. In over oxidation time, the oxidation of Co bottom layer and flat interface of insulator can increase the bottom Co coercivity. But TMR ratio gradually decrease. TMR ratio is relevant with Cr thickness, insulator thickness, and oxidation time. The maximum TMR ratio was 14% at room temperature and the TMR ratio was decreased to half at 0.51 V.

Improved Breakdown Voltage Characteristics of $In_{0.5}Ga_{0.5}P/In_{0.22}Ga_{0.78}As/GaAs$ p-HEMT with an Oxidized GaAs Gate

  • I-H. Kang;Lee, J-W.;S-J. Kang;S-J. Jo;S-K. In;H-J. Song;Kim, J-H.;J-I. Song
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.3 no.2
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    • pp.63-68
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    • 2003
  • The DC and RF characteristics of $In_{0.5}Ga_{0.5}P/In_{0.22}Ga_{0.78}As/GaAs$ p-HEMTs with a gate oxide layer of various thicknesses ($50{\;}{\AA},{\;}300{\;}{\AA}$) were investigated and compared with those of a Schottky-gate p-HEMT without the gate oxide layer. A prominent improvement in the breakdown voltage characteristics were observed for a p-HEMT having a gate oxide layer, which was implemented by using a liquid phase oxidation technique. The on-state breakdown voltage of the p-HEMT having the oxide layer of $50{\;}{\AA}$was ~2.3 times greater than that of a Schottky-gate p-HEMT. However, the p-HEMT having the gate oxide layer of $300{\;}{\AA}$ suffered from a poor gate-control capability due to the drain induced barrier lowering (DIBL) resulting from the thick gate oxide inspite of the lower gate leakage current and the higher on-state breakdown voltage. The results for a primitive p-HEMT having the gate oxide layer without any optimization of the structure and the process indicate the potential of p-HEMT having the gate oxide layer for high-power applications.

Effect of Si3N4 Buffer Layer on Transmittance of TiO2/Si3N4/Ag/Si3N4/TiO2 Multi Layered Structure (TiO2/Si3N4/Ag/Si3N4/TiO2 다층구조에서 Si3N4 버퍼층이 투과율에 미치는 영향)

  • Lee, Seo-Hee;Jang, Gun-Eik
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.1
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    • pp.44-47
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    • 2012
  • The $TiO_2/Si_3N_4/Ag/Si_3N_4/TiO_2$ multi layered structure was designed for the possible application of transparent electrodes in PDP (Plasma Display Panel). Multi layered film was deposited on a glass substrate at room temperature by DC/RF magnetron sputtering system and EMP (Essential Macleod Program) was adopted to optimize the optical characteristics of film. During the deposition process, the Ag layer in $TiO_2/Ag/TiO_2$ became heavily oxidized and the filter characteristic was degraded easily. In thus study, Si3N4 layer was used as a diffusion buffer layer between $TiO_2$ and Ag. in order to prevent the oxidation of Ag layer in $TiO_2/Si_3N_4/Ag/Si_3N_4/TiO_2$ structure. It was confirmed that $Si_3N_4$ layer is one of candidate materials acting as diffusin barrier between $TiO_2/Ag/TiO_2$.

Fabrication of Thick Silicon Dioxide Air-Bridge and Coplanar Waveguide for RF Application Using Complex Oxidation Process and MEMS Technology (복합 산화법과 MEMS 기술을 이용한 RF용 두꺼운 산화막 에어 브리지 및 공면 전송선의 제조)

  • Kim, Kook-Jin;Park, Jeong-Yong;Lee, Dong-In;Lee, Bong-Hee;Bae, Yong-Hok;Lee, Jong-Hyun;Park, Se-Il
    • Journal of Sensor Science and Technology
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    • v.11 no.3
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    • pp.163-170
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    • 2002
  • This paper proposes a $10\;{\mu}m$ thick oxide air-bridge structure which can be used as a substrate for RF circuits. The structure was fabricated by anodic reaction, complex oxidation and micromachining technology using TMAH etching. High quality films were obtained by combining low temperature thermal oxidation ($500^{\circ}C$, 1 hr at $H_2O/O_2$) and rapid thermal oxidation (RTO) process ($1050^{\circ}C$, 2 min). This structure is mechanically stable because of thick oxide layer up to $10\;{\mu}m$ and is expected to solve the problem of high dielectric loss of silicon substrate in RF region. The properties of the transmission line formed on the oxidized porous silicon (OPS) air-bridge were investigated and compared with those of the transmission line formed on the OPS layers. The insertion loss of coplanar waveguide (CPW) on OPS air-bridge was (about 2dB) lower than that of CPW on OPS layers. Also, the return loss of CPW on OPS air-bridge was less than about -20 dB at measured frequency region for 2.2 mm. Therefore, this technology is very promising for extending the use of CMOS circuitry to higher RF frequencies.

A Study on Temperature Dependence of Tunneling Magnetoresistance on Plasma Oxidation Time and Annealing Temperature (플라즈마 산화시간과 열처리 조건에 따른 터널링 자기저항비의 온도의존특성에 관한 연구)

  • Kim, Sung-Hoon;Lee, Seong-Rae
    • Journal of the Korean Magnetics Society
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    • v.14 no.3
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    • pp.99-104
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    • 2004
  • We have studied to understand the barrier and interface qualities and structural changes through measuring temperature dependent spin-polarization as functions of plasma oxidation time and annealing time. Magnetic tunnel junctions consisting of SiO2$_2$/Ta 5/CoFe 17/IrMn 7.5/CoFe 5/Al 1.6-Ox/CoFe 5/Ta 5 (numbers in nm) were deposited and annealed when necessary. A 30 s,40 s oxidized sample showed the lowest spin-polarization values. It is presumed that tunneling electrons were depolarized and scattered by residual paramagnetic Al due to under-oxidation. On the contrary, a 60s, 70 s oxidized sample might have experienced over-oxidation, where partially oxidized magnetic dead layer was formed on top of the bottom CoFe electrode. The magnetic dead layer is known to increase the probability of spin-flip scattering. Therefore it showed a higher temperature dependence than that of the optimum sample (50 s oxidation). temperature dependence of 450 K annealed samples was improved when the as-deposited one compared. But the sample underwent 475 K and 500 K annealing exhibits inferior temperature dependence of spin-polarization, indicating that the over-annealed sample became microstucturally degraded.