• Title/Summary/Keyword: materials science

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Microstructure and Properties of Yttria Film Prepared by Aerosol Deposition (에어로졸 데포지션에 의한 이트리아 필름의 미세구조와 특성)

  • Lee, Byung-Kuk;Park, Dong-Soo;Yoon, Woon-Ha;Ryu, Jung-Ho;Hahn, Byung-Dong;Choi, Jong-Jin
    • Journal of the Korean Ceramic Society
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    • v.46 no.5
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    • pp.441-446
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    • 2009

  • Dense crack-free yttria film with 10 $\mu m$ thickness was prepared on aluminum by aerosol deposition. X-ray diffraction pattern on the film showed that it contained the same crystalline phase as the raw powder. Transmission electron microscopy revealed a nanostructured yttria film with grains smaller than 100 nm. Tensile adhesion strength between the film and aluminum substrate was 57.8 $\pm$ 6.3MPa. According to the etching test with $CF_4-O_2$ plasma, the etching rate of the yttria film was 1/100 that of quartz, 1/10 that of sintered alumina and comparable to that of sintered yttria.

  • https://doi.org/10.4191/KCERS.2009.46.5.441 인용 PDF KSCI

Magnetotransport of Be-doped GaMnAs (GaMnAs의 Be 병행 도핑에 의한 자기 수송 특성 연구)

  • Im W. S.;Yoon T. S.;Yu F. C.;Gao C. X.;Kim D. J.;Ibm Y. E.;Kim H. J.;Kim C. S.;Kim C. O.
    • Korean Journal of Materials Research
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    • v.15 no.1
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    • pp.73-77
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    • 2005

  • Motivated by the enhanced magnetic properties of Mg-codoped GaMnN ferromagnetic semiconductors, Be-codoped GaMnAs films were grown via molecular beam epitaxy with varying Mn flux at a fixed Be flux. The structural, electrical, and magnetic properties were investigated. GaAs:(Mn,Be) films showed metallic behavior while GaAs:Mn films showed semiconducting behavior as determined by the temperature dependent resistivity measurements. The Hall-effect measurements with varying magnetic field showed clear anomalous Hall effect up to room temperature proving ferromagnetism and magnetotransport in the GaAs:(Mn,Be) films. Planar Hall resistance measurement also confirmed the properties. The dramatic enhancement of the Curie temperature in GaMnAs system was attributed to Be codoping in the GaMnAs films as well as MnAs precipitation.

  • https://doi.org/10.3740/MRSK.2005.15.1.073 인용 PDF KSCI