• Title/Summary/Keyword: Fe-Pt

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Dielectric properties of $Bi_{3.25}La_{0.75}Ti_3O_{12}$ thin films with Bi contents (Bi 첨가량에 따른 BLT 박막의 유전특성)

  • 김경태;김창일;강동희;심일운
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.371-374
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    • 2002
  • Bismuth lanthanum titanate thin films with excess Bi contents were prepared onto Pt/Ti/$SiO_2$/Si substrate by metalorganic decomposition (MOD) technique. The structure and morphology of the films were analyzed using X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. From the XRD analysis, BLT thin films show polycrystalline structure and the layered-perovskite phase was obtained over 10% excess of Bi contents. As a result of ferroelectric characteristics related to the Bi content of the BLT thin film, the remanent polarization and dielectric constant decreased with increasing over Bi content of 10 % excess. The BLT film with Bi content of 10% excess was measured to have a dielectric constant of n9 and dielectric loss of 1.85[%]. The BLT thin films showed little polarization fatigue test up to 3.5 x $10^{9}$ bipolar switching cycling.

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Elemental Correlations of Chemical Compositions in Co-rich Mn-crusts of the Republic of Marshall Islands (마샬공화국 고코발트망간각 화학조성의 원소 상관관계)

  • 황의덕;장세원;김두영
    • Journal of the Mineralogical Society of Korea
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    • v.12 no.2
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    • pp.77-90
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    • 1999
  • Characteristics and variations of chemical compositions in Co-rich crusts occurred in the EEZ of the Republic of Marshall Islands were reviewed. Correlation coefficient analysis, hierarchical cluster analysis, and Q-mode factor analysis for 62 samples were done in this study. All data were selected and gathered from the open file report of the cooperative cruise done by United States Geological Survey with Scripps Institute of Oceanography, University of Hawaii or Korea Ocean Research Development Institute. The average of crust thickness. Co content, and Ni content of 62 samples from the 21 seamounts were 30mm, 0.58 wt% and 0.40%, respectively. The mineral phases and associated elements assigned by correlation coefficients, cluster analysis and Q-mode factor analysis are following four. 1) CFA: P, Ca, CO2, Y, Sr: 2) Mn-oxide mineral: As, Mn, Co, Na: 3) Al-silicate mineral: Pd,Si, Al, Cu, Fe: 4) PGE-bearing mineral: Rh, Pt, Ir.

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Poling-dependent Ferroelectric Properties of SBN30 Thin Films (분극에 의한 SBN30 박막의 강유전특성 변화)

  • Jang, Jae-Hoon;Lee, Dong-Gun;Lee, He-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.309-312
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    • 2002
  • Ferroelectric $Sr_{0.3}Ba_{0.7}Nb_{2}O_{6}$ (SBN30) thin films were deposited on Pt/Ti/$SiO_{2}$/Si(100) substrates by ion beam sputtering. During annealing treatment at $750^{\circ}C$, poling was attempted by applying dc voltage bias across polished surfaces. Phase relation, microstructure and crystallization behavior were examined using XRD and FE-SEM. Ferroelectric hysteresis characteristics were also determined where both remanent polarization and coercive values decreased with the increase of bias voltage. The measured remanent polarization and coercive field values at 5 V and 10 V bias were $36{\mu}C/cm^2$, $10{\mu}C/cm^2$ and 100kV /cm, 80kV /cm, respectively.

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Current-induced Spin Wave Excitations in Asymmetric Nanopillar Junctions

  • Fiandimas, Arie;Lee, Kyung-Jin;Shin, Kyung-Ho
    • Journal of Magnetics
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    • v.14 no.2
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    • pp.90-92
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    • 2009
  • This study examined the current-induced spin wave excitation in asymmetric nanopillar junctions with a stack sequence of 20 nm Pt/10 nm Cu/7 nm NiFe/300 nm Cu, and a circular lateral dimension of 240 nm. An analysis of the magnetic and magnetotransport characteristics of the junction showed a possible spin transfer effect at this sample dimension when the magnetization was switched from a vortex state to another state. This finding is expected to help improve the understanding of the spin transfer torque phenomenon in nanopillar junctions.

새로운 Ge 전구체의 CVD 증착 특성연구

  • Jeon, Gi-Mun;Ha, Hong-Sik;Yeom, Ho-Yeong;Choe, Jeong-Hyeon;Yun, Ju-Yeong;Gang, Sang-U
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.250-250
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    • 2013
  • 본 연구에서는 차세대 상변화메모리(PCRAM)와 초고속 소자(FET) 등의 응용을 위하여 사용되고 있는 Ge 소재를 제조하기 위해새롭게 전구체를 개발하고 이를 CVD (Chemical Vapor Deposition) 공정을 이용하여 증착실험을 실시하였다. 새롭게 개발된 Ge 전구체 (isopropyl germane)는 기존 Ge 전구체보다 합성비용이 경제적이며 공정이 간단하고 상업적 생산에도 적합하다는 장점을 갖고 있다. Ge 박막의 증착은 증착압력, 증착온도, reactive gas (H2) 유량, carrier gas(Ar) 유량, 기판(Si, Pt 등) 등을 변수로 하여 실험하였다. 증착된 박막에 대하여 FE-SEM, XRD 등을 통하여 기본적인 물성분석을 실시하였다.

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Ferroelectirc Properties of Sm-doped PZT Thin films (Sm이 첨가된 PZT 박막의 강유전 특성)

  • 손영훈;김경태;김창일;이병기;장의구
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.2
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    • pp.178-183
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    • 2004
  • PBT thin film was known to be a representative for the FeRAM devices because of its good ferroelectric proporties and the ease in fabricating the thin film. However, there have been several problems such as polarization fatigue and leakage current in memory devices with a PZT thin film. In this study, Sm-dolled PZT thin films were fabricated by the so1-gel method, and their ferroelectric and dielectric proportrics were compared as a function of Sm content. We investigated the effect of the Sm dopant on structural and electrical properties of PZT film. Sm-doped PZT thin films on the Pt/Ti/SiO$_2$/Si substrates have been prepared by a sol-gel method. The remanent polarization and coercive field decreased with increasing the concentration of Sm. The dielectric constant and dielectric loss decreased with Increasing Sm content. Sm-doped PZT thin films showed improved fatigue characteristics compared to the undoped PZT thin film.