• Title/Summary/Keyword: Liquid phase epitaxy

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Growth of YIG Thick Films by the Change of Supercooling and Substrate Rotation Speed (과냉도 및 기판회전조건 변화에 따른 YIG 단결정 후막의 성장)

  • Kim, Yong-Tak;Yoon, Seok-Gyu;Kim, Geun-Young;Im, Young-Min;Jang, Hyun-Duck;Yoon, Dae-Ho
    • Journal of the Korean Ceramic Society
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    • v.39 no.5
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    • pp.498-502
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    • 2002
  • Pure-yttrium iron garnet($Y_3Fe_5O_{12}$2, YIG) thick films were grown from a $PbO/B_2O_3$ flux onto (111) SGGG substrate using liquid phase epitaxy. The effect of substrate rotation speed and supercooling on crystallinity, chemical composition and growth rate of the thick films was investigated. The FWHM of films decreased with increasing of growth temperature from 860 to 910${\circ}C$. A substrate rotation speed of 120 rpm at 910${\circ}C$ lead to growth rates up to $60{\mu}m/h$.

The effect of melt instability on the liquid phase epitaxy (용액 불안정이 InGaAsP/InP 액상결정성장에 미치는 영향)

  • 오수환;안세경;홍창희
    • Korean Journal of Optics and Photonics
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    • v.8 no.5
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    • pp.438-442
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    • 1997
  • In this study we report the effect of melt instability on the Liquid Phase Epitaxy. We made a new graphite boat of the structure relieving the instability of melt. It did not improve the uniformity of each layers but also reduced the thickness of growth layers and the deviation of the thickness over 1/2, 1/3 respectively. Moreover, we could get the growth layer of about 80$\AA$. With the point of melt stability in view we investigated the effect of InP seed used in two phase solution method. It is concluded that the quality of layers grown by the single crystal is superior to that by the poly crystal in two phase solution method.

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Direct synthesis mechanism of amorphous $SiO_x$ nanowires from Ni/Si substrate (Ni/Si 기판을 사용하여 성장시킨 비결정질 $SiO_x$ 나노 와이어의 성장 메커니즘)

  • Song, W.Y.;Shin, T.I.;Lee, H.J.;Kim, H.;Kim, S.W.;Yoon, D.H.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.16 no.6
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    • pp.256-259
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    • 2006
  • The amorphous $SiO_x$ nanowires were synthesized by the vapor phase epitaxy (VPE) method. $SiO_x$ nanowires were formed on silicon wafer of temperatures ranged from $800{\sim}1100^{\circ}C$ and nickel thin film was used as a catalyst for the growth of nanowires. A vapor-liquid-solid (VLS) mechanism is responsible for the catalyst-assisted amorphous $SiO_x$ nanowires synthesis in this experiment. The SEM images showed cotton-like nanostructure of free standing $SiO_x$ nanowires with the length of more than about $10{\mu}m$. The $SiO_x$ nanowires were confirmed amorphous structure by TEM analysis and EDX spectrum reveals that the nanowires consist of Si and O.

Temperature Dependence of Magnetostatic Waves on the YIG Single Crystalline Thin Film (YIG 단결정 박막에 대한 정자파의 온도의존성 연구)

  • Lee, Soo-Hyung
    • Journal of the Korean Magnetics Society
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    • v.12 no.5
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    • pp.163-167
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    • 2002
  • In order to study the temperature dependence of the magnetostatic wave modes for an YIG thin film, grown by a liquid phase epitaxy method, The ferromagnetic resonance was performed by an FMR spectrometer in the temperature range -140$\^{C}$∼200$\^{C}$. The magnetostatic surface wave and backward volume wave modes show periodic excitations in parallel configuration. The resonance fields of all modes and intensities decreased with decreasing the temperature. All magnetostatic modes can be well explained by the Walker and Damon-Eshbach theory. The calculated saturation magnetization Ms of the YIG thin film was increased with decreasing the temperature. The line widths of magnetostatic modes changed in various trends with decreasing the temperature.

Optimization of $p^+$ seeding layer for thin film silicon solar cell by liquid phase epitaxy

  • Lee, Eun-Joo;Lee, Soo-Hong
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.15 no.6
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    • pp.260-262
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    • 2005
  • Thickness optimization of heavily doped p-type seeding layer was studied to improve performance of thin film silicon solar cell. We used liquid phase epitaxy (LPE) to grow active layer of $25{\mu}m$ thickness on $p^+$ seeding layer. The cells with $p^+$ seeding layer of $10{\mu}m\;to\;50{\mu}m$ thickness were fabricated. The highest efficiency of a cell is 12.95%, with $V_{oc}=633mV,\;J_{sc}=26.5mA/cm^2$, FF = 77.15%. The $p^+$ seeding layer of the cell is $20{\mu}m$ thick. As thicker seeding layer than $20{\mu}m$, the performance of the cell was degraded. The results demonstrate that the part of the recombination current is due to the heavily doped seeding layer. Thickness of heavily doped p-type seeding layer was optimized to $20{\mu}m$. The performance of solar cell is expected to improve with the incorporation of light trapping as texturing and AR coating.

Ferromagnetic Resonance Study of an YIG Thin Film Grown by LPE Method (LPE법으로 제조한 YIG 박막에 대한 강자성공명 연구)

  • 이수형;염태호;윤달호;김약연;한기평;이상석
    • Journal of the Korean Magnetics Society
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    • v.9 no.2
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    • pp.85-90
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    • 1999
  • The ferromagnetic resonance study of the magnetostatic wave modes for an YIG thin film, grown by a liquid phase epitaxy method, was performed by an FMR spectrometer at room temperature. The magnetostatic surface wave and backward volume wave modes show periodic excitations in parallel configuration, whereas the complex spectra were observed in perpendicular configuration. The resonance spectra in parallel configuration can be well explained by the Walker and Damon-Eshbach theory. The peak-peak line width of uniform mode was 0.4 Oe. The saturation magnetization $M_s$ of the YIG thin film was calculated as 137 emu/㎤. In order to know the dependence of the magnetostatic modes as a function of the saturation magnetization and the thickness, the (1,1) and (3,1) modes of the magnetostatic backward volume wave were compared and theoretically calculated.

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Effect of Annealing for YIG Single Crystal Thick Films (YIG 단결정 후막의 열처리의 효과)

  • 김근영;윤석규;김용탁;이성문;윤대호
    • Journal of the Korean Ceramic Society
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    • v.40 no.9
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    • pp.855-858
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    • 2003
  • When the PbO-based flux system is used in the Liquid Phase Epitaxy (LPE) method for Yttrium Iron Garnet (YIG) thick film, the effect of Pb ions incorporated into the grown crystal; increase the lattice parameter, changed the uniaxial magnetic anisotropy constant (Ku) or conductance of grown film. It exerts a bad influence on physical property such as increasing optical absorption of grown film. The content of the Pb ion in crystal was decreased by volatilization of Pb ion after annealing; therefore, the lattice parameter of film was reduced on an average 0.0115 ${\AA}$ by the the Pb ion.

Growth and magnetic properties of Tb, Eu, EuTb-substituted garnet single crystal films (Tb, Eu, EuTb가 치환된 가네트 단결정 막의 성장과 자기적 특성)

  • Kim G. Y;Yoon S. G.;Chung I. S;Park S. B;Yoon D. H
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.14 no.5
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    • pp.193-198
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    • 2004
  • Using the $PbO-B_2O_3-Bi_2O_3$ flux system, $(TbBi)_3(FeAIGa)_5O_{12}(TbIG)$, $(EuBi)_3(FeAIGa)_5O_{12}(EuIG)$ and $(EuTbBi)_3(FeAIGa)_5O_{12}(EuTbIG)$ films were grown on $(GdCa)_3(GaMgZr)_5O_{12}(SGGG)$ substrates by the liquid phase epitaxy (LPE). The saturation magnetization of the grown TbIG, EuIG and EuTbIG films was about 150, 950 and 125 Oe, respectively. The TbIG films resulted in the single magnetic domain while the EuIG and EuTbIG films were observed to be the multi magnetic domains by magnetic force microscope (MFM).