• Title/Summary/Keyword: oriented thick film

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The Role of (111)MgO Underlayer in Growth of c-axis Oriented Barium Ferrite Films

  • Erickson, D.W.;Hong, Y.K.;Gee, S.H.;Tanaka, T.;Park, M.H.;Nam, I.T.
    • Journal of Magnetics
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    • v.9 no.4
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    • pp.116-120
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    • 2004
  • Hexagonal barium-ferrite ($BaFe_{12}O_{19}$, magnetoplumbite structure; BaM) film with perpendicularly c-axis orientation was successfully deposited on (100) silicon substrates with an MgO (111) underlayer by rf diode sputtering and in-situ heating at $920^{\circ}C$. The magnetic and structural properties of 0.27 ${\mu}m$ thick BaM films on MgO (111) underlayers were compared to films of the same thickness deposited onto single-crystal MgO (111) and c-plane ($000{\ell}$) sapphire ($Al_2O_3$) substrates by vibrating sample magnetometry (VSM), x-ray diffractometer (XRD), and atomic force microscopy (AFM). The thickness dependence of MgO (111) underlayers on silicon wafer was found to have a large effect on both magnetic and structural properties of the BaM film. The thickness of 15 nm MgO (111) underlayers produced BaM films with almost identical magnetic and structural properties as the single-crystal substrates; this can be explained by the lower surface roughness for thinner underlayer thicknesses. The magnetization saturation ($M_s$) and the ratio $H_{cII}/H_{c{\bot}}$ for the BaM film with a 15 nm MgO (111) underlayer is 217 emu/cc and 0.24, respectively. This is similar to the results for the BaM films deposited on the single-crystal MgO (111) and sapphire substrates of 197 emu/cc and 0.10, 200 emu/cc and 0.12, respectively. Therefore, the proposed MgO (111) underlayer can be used in many applications to promote c-axis orientation without the cost of expensive substrates.

The Effects of CdO Addition on the Orientation Process of Bi-Sr-Ca-Cu-O Supercoducting Thick Film (Bi계 초전도 후막의 배향과정에 CdO 첨가의 영향)

  • 한영희;성태현;한상철;이준성;정상진
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 1999.02a
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    • pp.47-50
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    • 1999
  • The orientation mechanism of an amorphous $Bi_{2}$$Sr_{2}$$Ca_{2 x}$$Cd_{x}$$Cu_{3}$$O_{y}$ phase were studied by using the dilatometry. The amorphous $Bi_{2}$$Sr_{2}$$Ca_{2 x}$$Cd_{x}$$Cu_{3}$$O_{y}$ samples brought about a volume shrinkage at the onset of the crystallization of a $Bi_{2}$$Sr_{2}$$CaCu_{2}$$O_{6}$phase around $400^{\circ}C$. The random crystal growth of $Bi_{2}$$Sr_{2}$$CaCu_{2}$$O_{8}$ phase around $800^{\circ}C$. yielded a rapid volume expansion and after then samples shrinmed, accompanied with the crystal orientation. The$Bi_{2}$$Sr_{2}$$Ca_{2 x}$$Cd_{x}$$Cu_{3}$$O_{y}$ (x=0.4) sample exhibited the best-oriented structure because the liquid phase formed seemed to have the lowest viscosity which would contributed to the easy collapse of the card-house structure.

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A Study on the Characteristics of TSC for BOPP Irradiatied by $Co^{60}-{\gamma}$ ray ($Co^{60}-{\gamma}$ 선으로 조사된 이축 연신된 폴리프로필렌 필름의 열자격 특성에 관한 연구)

  • Song, K.Y.;Park, S.H.;Ryu, B.H.;Hong, J.W.;Lee, J.U.;Kim, B.H.
    • Proceedings of the KIEE Conference
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    • 1990.07a
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    • pp.195-198
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    • 1990
  • In order to investigate the radiation effects induced to electrical properties of Biaxially-Oriented Polypropylen film, several observations were carried out to the sample irradiated to various dose by $Co^{60}-{\gamma}$ ray, on the characteristics of TSC spectra measuered as a function of electric field applied to a sample of 15[ ${\mu}m$] thick. The TSC spectra observed in the temperature range of $153{\sim}403[K]$ with the electric field of intensity $10{\sim}60$ [MV/m], have shown two of the distinguished peak such as ${\beta}$, ${\alpha}$, each of which appeared at $-5{\sim}20$ [ $^{\circ}C$] and 90 [ $^{\circ}C$] respectively. As the conclusions, obtained from the studies, the origin of ${\alpha}$ peak in TSC seems to be attributed by thermal excitation of ions trapped with $0.4{\sim}0.8[eV]$ deep, at the defects formed by $Co^{60}-{\gamma}$ irradiation in a crystaline region. The origin of ${\beta}$ peak was regarded as the depolarization process of "OH" or "CO" dipole with the activation energy of $0.4{\sim}0.6[eV]$ in an amorphous region.

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A study on the properties of TSC in oriented polypropylene film irradiated by laser (레이저로 조사된 이축연신 폴리프로필렌 필름의 열자격 전류특성에 관한 연구)

  • 노영배;홍진웅;김재환;이준웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1990.10a
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    • pp.98-101
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    • 1990
  • In order to investigate the laser effects resulted from the behaviors of carriers for BOPP film, experiment of TSC were carried out on the specimen with 15[$\mu\textrm{m}$] thick irradiated by He-Ne laser. The TSC spectras were observed in the temperature range of -100[$^{\circ}C$] to 130[$^{\circ}C$] with the electric field of 20∼60[MV/m], had show four of the distinguished peak such as ${\alpha}$$_1$, ${\alpha}$$_2$, ${\beta}$ and ${\gamma}$, which appeared at 115, 80, 17 and -30[$^{\circ}C$] respectively. Specially, ${\alpha}$$_1$ was observed and anomalous TSC flowing in the same direction as the charging current on the high-electric field such as 50∼60[MV/m]. In according on the consequences obtained from the studies, the origin of ${\alpha}$$_1$peak was attributed to the detrapping process form trap with 2.88[eV] deep of injected space charge from the chathode in the crystaline regions. The origin of ${\alpha}$$_2$ peak was regarded as the detrapping process of ions trapped with 0.9[eV] deep originated from impurity-ion remained in the specimen during production process of the material, in the crystalline regions. The origin of ${\beta}$ peak was concluded to be due to the depolarization process of "C=0"dipole with the activation energy of 0.75[eV] in the amorphous regions. The origin of ${\gamma}$ peak was responsible to the process combined with the depolarization of "CH$_3$", chain segment, with the activation energy of carriers from the shallow trap with 0.4[eV], in he amorphous regions.

Effect of postharvest CO2 treatment on the quality of the 'Gonji-7ho' oyster mushroom (Pleurotus ostreatus) during oriented polypropylene packaging and storage (수확 후 CO2처리가 느타리버섯 곤지7호의 OPP 포장 저장 중 품질에 미치는 영향)

  • Choi, Ji-Weon;Lee, Ji-Hyun;Kim, Chang-Kug;Shin, Il-Sub;Bae, Yeoung-Seuk
    • Journal of Mushroom
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    • v.18 no.1
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    • pp.115-119
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    • 2020
  • This study was conducted to investigate the effect of post-harvest CO2 treatment on the quality of the 'Gonji-7ho' oyster mushroom. The harvested mushrooms were pre-cooled at 3℃ for 1 day and placed in a gas-tight chamber with 0%, 30%, or 50% of CO2 concentration for 3 hours at 3℃. Next, 400 g of the oyster mushroom sample was packaged into 20-㎛ thick oriented polypropylene (OPP) film bags and stored at 4℃ for 21 days. Treatment with 30% of CO2 treatment maintained the highest stipe firmness of the oyster mushrooms during storage. The stipe lightness (CIE L) was the highest at 14 and 21 days, while the stipe yellowness (CIE b) was the lowest at 2 and 7 days of storage. Therefore, we concluded that the 30% CO2 treatment maintained the overall visual quality of the 'Gonji-7ho' oyster mushroom until 17 days of storage at 3℃. Our results suggest that the shelf life of 'Gonji-7ho' oyster mushroom could be extended by the postharvest application of 30% CO2 for 3 hours during low temperature storage.