• 제목/요약/키워드: multicomponent materials

검색결과 54건 처리시간 0.035초

$Ga_2O_3$ 첨가에 따른 다성분계 glass optical fiber의 특성 (Properties of Multicomponent Glass Optical Fiber by adding $Ga_2O_3$)

  • 윤상하;강원호
    • E2M - 전기 전자와 첨단 소재
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    • 제10권3호
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    • pp.210-216
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    • 1997
  • The th ermal and optical properties of multicomponent oxide glass optical fiber by adding heavy metal oxide Ga$_{2}$O$_{3}$(0-20wt%) were investigated. The fiber samples were made by the method of rod in tube. The optical loss of fiber was measured in 0.3-1.8.mu.m wavelength region. As Ga$_{2}$O$_{3}$ increased up to 20wt%, the transition and softening temperature of bulk glass were increased from 495.deg. C to 579.deg. C and from 548.deg. C to 641.deg. C, respectively. Whereas the thermal expansion coefficient was decreased from 102 to 79.1x10$^{-7}$ /.deg. C. The refractive index was increased from 1.621 to 1.665, and IR cut-off wavelength was enlarged from 4.64.mu.m to 6.1.mu.m. The optical loss of fiber was remarkably decreased in 1.146.mu.m-1.8.mu.m wavelength region.

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동적재료모델에 의한 벌크 비정질 금속의 판재성형성에 대한 고찰 (Dynamic Materials Model-Based Study on the Formability of Bulk Metallic Glass Sheets)

  • 방원규;이광석;안상호;장영원
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2002년도 춘계학술대회 논문집
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    • pp.173-176
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    • 2002
  • Viscoplastic deformation and sheet forming behavior of multicomponent Zr-based bulk metallic glass alloy has been investigated. From a series of mechanical test results, basic processing maps based on Dynamic Materials Model have been constructed to establish feasible forming conditions. Stamping in laboratory scale was then performed at the various stroke speeds and temperatures using a hydraulic press. Failure in macroscopic level was examined to check the validity of constructed processing maps.

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Synthesis of Sulfide-based Phosphors by Multiply Combined Methods Based Upon Inorganic Chemistry

  • Kakihana, Masato;Petrykin, Valery
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.121-124
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    • 2009
  • We developed a panel of innovative solution-based approaches for synthesis of multicomponent sulfide phosphor materials. The application of these synthesis strategies allowed for preparation of high-purity and high-brightness $BaAl_2S_4:Eu$ and $Ba_2SiS_4:Eu$ phosphors and led to the discovery of new phosphors suitable for application in the LED-based lighting including $Sr_2ZnS_3:Eu$, $CaBaSiS_4:Eu$ and $(Ba,Sr)_2ZnS_3:Eu$.

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Preparation of Paraelectric PLT Thin Films Using Reactive Magnetron Sputtering of Multicomponent Metal Target

  • Kim, H.H.;Sohn, K.S.;Casas, L.M.;Pfeffer, R.L.;Lareau, R.T.
    • E2M - 전기 전자와 첨단 소재
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    • 제11권10호
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    • pp.53-59
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    • 1998
  • Paraelectric lead landthanum titanate(PLT) thin films have been prepared by a reactive dc magnetron sputtering system using a multicomponent metal target. The surface area control of each element on the target markedly facilitates the fabrication of thin films of complex ceramic compounds. A postdeposition heat-treatment was applied to all as-deposited PLT thin films at annealing temperatures up to 75$0^{\circ}C$ for crystalization. The composition of the PLT(28) thin filmannealed at $650^{\circ}C$ was: Pb, 0.73; La, 0.28; Ti, 0.88; O, 2.9. The dielectric constant and dissipation factor of the thin film(200 nm) at low filed measurements (500 Vcm-1) are 1216 and 0.018, respectively. The charge storage density using a typical Sawyer-Tower circuit with a 500 Hz sine wave was 12.5 $\mu$Ccm-2 at the electric field of 200 kVcm-1.

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다성분계 물성을 예측하기 위한 BaTiO3기반 계산과학 플랫폼 구축 (Establishment of a BaTiO3-based Computational Science Platform to Predict Multi-component Properties)

  • 이동건;이한욱;임원빈;고현석;조성범
    • 센서학회지
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    • 제31권5호
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    • pp.318-323
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    • 2022
  • Barium titanate (BaTiO3) is considered to be a beneficial ceramic material for multilayer ceramic capacitor (MLCC) applications because of its high dielectric constant and low dielectric loss. Numerous attempts have been made to improve the physical properties of BaTiO3 in response to recent market trends by employing multicomponent alloying strategies. However, owing to its significant number of atomic combinations and unpredictable physical properties, finding a traditional experimental approach to develop multicomponent systems is difficult; the development of such systems is also time-consuming. In this study, 168 new structures were fabricated using special quasi-random structures (SQSs) of Ba1-xCaxTi1-yZryO3, and 1680 physical properties were extracted from first-principles calculations. In addition, we built an integrated database to manage the computational results, and will provide big data solutions by performing data analysis combined with AI modeling. We believe that our research will enable the global materials market to realize digital transformation through datalization and intelligence of the material development process.

Powder Injection Molding of Alumina Parts Using a Binder System Based in Paraffin Wax and High Density Polyethylene

  • Thomas-Vielma, P.;Cervera, A.;Levenfeld, B.;Varez, A.
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.207-208
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    • 2006
  • In this experimental work, the development of a multicomponent binder system based on high density polyethylene (HDPE) and paraffin wax for Powder Injection Molding of Alumina $(Al_2O_3)$ parts was carried out. The optimum composition of the injection mixture was established through mixing torque measurements and a rheological study. The maximum powder loading was 58 vol%. The miscibility of organic components and the optimum injection temperature was evaluated by thermal characterization of binder and feedstock. The thermal debinding cycle was developed on the basis of thermogravimetrical analysis of the binder. After sintering the densities achieved were closed to 98% of the theoretical one.

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Multicomponent wide band gap oxide semiconductors for thin film transistors

  • Fortunato, E.;Barquinha, P.;Pereira, L.;Goncalves, G.;Martins, R.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.605-608
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    • 2006
  • The recent application of wide band gap oxide semiconductors to transparent thin film transistors (TTFTs) is making a fast and growing (r)evolution on the contemporary solid-state electronics. In this paper we present some of the recent results we have obtained using wide band gap oxide semiconductors, like indium zinc oxide, produced by rf sputtering at room temperature. The devices work in the enhancement mode and exhibit excellent saturation drain currents. On-off ratios above $10^6$ are achieved. The optical transmittance data in the visible range reveals average transmittance higher than 80 %, including the glass substrate. Channel mobilities are also quite respectable, with some devices presenting values around $25\;cm^2/Vs$, even without any annealing or other post deposition improvement processes. The high performances presented by these TTFTs associated to a high electron mobility, at least two orders of magnitude higher than that of conventional amorphous silicon TFTs and a low threshold voltage, opens new doors for applications in flexible, wearable, disposable portable electronics as well as battery-powered applications.

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다성분계 산화물의 요업재료 제조를 위한 석유 증발 건조 방법 (Hot Petroleum Drying Method to the Preparation of Multicomponent Oxide Ceramic Material)

  • 변수일
    • 한국세라믹학회지
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    • 제14권3호
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    • pp.163-168
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    • 1977
  • As a wet chemical drying process "hot petroleum drying method" was applied and developed for preparing uniformly fine oxide powder with high purity and sinterreactivity. Using this method solution of sulfates was dried in hot petroleum bath (~17$0^{\circ}C$) to sulfate powder from which corresponding mullite doped by Fe3+ ion was formed. Particle size, shape, decomposition by heat, and phase identification of sulfate andoxide powders determined by DTA, TGA, X-ray diffraction, analysis and electron microscopy: sulfate powder prepared by this drying method is an intimate mixture of the amorphous form of uniformly and finely distributed spherical particles (0.05-0.1$\mu$). Mullitization with the sulfate powder occurs at 110$0^{\circ}C$ in air. The morphology of mullite particle made by firing the sulfate powder at 135$0^{\circ}C$ in oxygen atmosphere is granular of 0.1-0.3$\mu$ in size. This drying process proved to be a very effective method for preparing fine, homogeneous, and highly sinterreactive multicomponent oxide powder without conventional ceramic process of mixing, milling, and granulating. This process can be also applied for preparing electronic ceramic materials which are requisite for high purity and homogeneity.mogeneity.

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