• 제목/요약/키워드: Inorganic materials

검색결과 1,814건 처리시간 0.036초

Carbon Nanotube Synthesis and Growth Using Zeolite by Catalytic CVD and Applications

  • Zhao, Wei;Nam, Seo Dong;Pokhrel, Ashish;Gong, Jianghong;Kim, Ik Jin
    • 한국세라믹학회지
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    • 제50권1호
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    • pp.1-17
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    • 2013
  • Since their first discovery, carbon nanotubes (CNTs) have become a material central to the field of nanotechnology. Owing to their splendid physical, structural and chemical properties, they have the potential to impact a wide range of applications, including advanced ceramics, nanoelectronic devices, nanoscale sensors, solar cells, battery electrodes, and field emitters. This review summarizes the synthetic methods of preparing CNTs and focuses on the chemical vapor deposition (CVD) method, especially catalytic CVD. In order to stabilize and disperse the catalyst nanoparticles (NPs) during synthesis, zeolite was implemented as the template to support metal-containing NPs, so that both CNTs in the bulk and on a 2D substrate were successfully synthesized. Despite more challenges ahead, there is always hope for widespread ever-new applications for CNTs with the development of technology.

이종 집적 유연 반도체 시스템 구현을 위한 무기물 박막소재의 전사 방법 (Transfer Methods of Inorganic Thin Film Materials for Heterogeneously- Integration Flexible Semiconductor System)

  • 주경현;김정현;박상윤;김강현;이한얼
    • 한국전기전자재료학회논문지
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    • 제37권3호
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    • pp.241-252
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    • 2024
  • With the recent development of emerging technologies, information acquisition and delivery between users has been actively conducted, and inorganic thin film transfer technology that effectively transfers various materials and devices is being studied to develop flexible electronic devices accordingly. This is aimed at innovative structural changes and functional improvement of electronic devices in the era of the Internet of Things (IoT). In particular, advanced technologies such as microLEDs are used to realize high-resolution flexible displays, and the possibility of heterogeneous integrated technologies can be presented by precisely transferring materials to substrates through various transfer process. This paper introduced physical, chemical, and self-assembly transfer methods based on inorganic thin film materials to implement heterogeneous integrated flexible semiconductor systems and introduces the results of application studies of semiconductor devices obtained through different transfer technologies. These studies are expected to bring about innovative changes in the field of smart devices, medical technology, and user interfaces in the future.

Verneuil법에 의한 $TiO_2$를 첨가한 Sapphire 단결정 성장과 결함에 관한 연구 ($TiO_2$ Doped Sapphire Single Crystal Growth by Verneuil Method and Study for Defects)

  • 조현;최종건;전병식;오근호;박한수
    • 한국세라믹학회지
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    • 제31권12호
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    • pp.1423-1428
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    • 1994
  • TiO2 doped sapphire single crystals were grown by Verneuil method. The doping amount of TiO2 to Al2O3 were varied 0.1, 0.2, 0.3 wt% respectively. The grown crystals have reddish color and somewhat transparent. Optimum growth condition was established by changing growth rate and gas flow ratio. Growth condition are as follows; The flow rate range of oxygen ws 5.0~7.3 ι/min and that of hydrogen was 16~25ι/min and average growth rate was 6~8mm/hr. The basic cause of color appearence and defects in crystal were studied.

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Properties of Silicon Carbide-Carbon Fiber Composites Prepared by Infiltrating Porous Carbon Fiber Composites with Liquid Silicon

  • Lee, Jae-Chun;Park, Min-Jin;Shin, Kyung-Sook;Lee, Jun-Seok;Kim, Byung-Gyun
    • The Korean Journal of Ceramics
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    • 제3권4호
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    • pp.229-234
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    • 1997
  • Silicon carbide-carbon fiber composites have been prepared by partially Infiltrating porous carbon fiber composites with liquid silicon at a reaction temperature of $1670^{\circ}C$. Reaction between molten silicon and the fiber preform yielded silicon carbide-carbon fiber composites composed of aggregates of loosely bonded SiC crystallites of about 10$\mu\textrm{m}$ in size and preserved the appearance of a fiber. In addition, the SiC/C fiber composites had carbon fibers coated with a dense layer consisted of SiC particles of sizes smaller than 1$\mu\textrm{m}$. The physical and mechanical properties of SiC/C fiber composites were discussed in terms of infiltrated pore volume fraction of carbon preform occupied by liquid silicon at the beginning of reaction. Lower bending strength of the SiC/C fiber composites which had a heterogeneous structure in nature, was attributed to the disruption of geometric configuration of the original carbon fiber preform and the formation of the fibrous aggregates of the loosely bonded coarse SiC particles produced by solution-precipitation mechanism.

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Effect of Aggregates on the Microstructure in Manganese Zinc Ferrite

  • Shin, Hyo-Soon;Lee, Dae-Hee;Kim, Chang-Bum;Kim, Nam-Kyung;Lee, Suk-Kee;Lee, Byung-Kyo
    • 한국세라믹학회지
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    • 제40권1호
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    • pp.1-4
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    • 2003
  • To study the effect of aggregates on the microstructure of sintered bodies, Mn-Zn ferrite powders were prepared by an alcoholic dehydration method. Aggregate powders and reground powders were used as seeds and matrices, respectively. The mixing ratios for the aggregate and reground powders were varied with the sintering temperatures. Green densities were measured with changes in forming pressure and they were related to the microstructures of the sintered bodies. The aggregates proved to be capable of acting as seeds for abnormal grain growth. When the green density difference between the aggregate and the matrix was large, the aggregate could become the seed of abnormal grain growth. As the forming pressure increased, the more aggregates became seeds of abnormal grain growth.

$KTP(KTiOPO_4)$단결정 육성 및 물성 연구 (A study on the growth and properties of KTP single crystals)

  • 이명준;차용원;장지연;오근호;김판채
    • 한국결정성장학회지
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    • 제4권1호
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    • pp.100-104
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    • 1994
  • KTP 종자결정의 육성을 수열법에 의해 행하였으며, 육성결정의 물성은 적외분광 광도계를 이용하여 조사하였다.종자결정의 육성에 있어 큰 성장속도를 나타내는 수열 조건은 다음과 같다. 즉, 온도범위,$430~450^{\circ}C $ ; 수열용매, 4몰 KF용액 ; 온도차, $30<{\triangle}T<65^{\circ}C$ ; 충진율%, 65% ; 육성방법, 수직온도 구배법. 이와 같은조건하에서 얻어진 KTP단 결정의 형태는(100), (011), (201)면이 잘 발달하는 경향이 있었으며 그리고 육성결정 중에는hydroxyl group이 존재하였다.

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