• Title/Summary/Keyword: $Bi_O_3$

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Effects of lanthanum doping on ferroelectric properties of direct-patternable $Bi_{4-x}La_xTi_3O_{12}$ films prepared by photochemical metal-organic deposition

  • Park, Hyeong-Ho;Kim, Hyun-Cheol;Park, Hyung-Ho;Kim, Tae-Song
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.287-287
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    • 2007
  • The ferroelectric and electric properties of UV-irradiated bismuth lanthanum titanate (BLT) films prepared using photosensitive starting precursors were characterized. The effects of lanthanum doping on ferroelectric and electric properties were investigated by polarization-electric field hysteresis loops and leakage current-voltage measurements. X-ray diffractometer and ellipsometry were served to provide the information about the crystalline structure and thickness of the films after annealing. The images of the surface microstructure and direct-patterned BLT films were observed by using scanning electron microscopy. The effects of lanthanum doping on the electric properties of direct-pattern able BLT films and their direct-patterning were studied.

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Fabrication of BSCCO High Tc Superconducting Precursor (BSCCO 초전도 전구체의 합성)

  • Lee, Sang-Heon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.290-291
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    • 2005
  • A high Tc superconducting with a nominal composition of $Bi_2Sr_2Ca_2Cu_3O_Y$ was prepared by the citarte method. The solid precursor produced by the dehydration of the gel at $120^{\circ}C$ for 12h is not in the amorphous state as expected but in a crystalline state. X-ray diffraction peaks of nearly the same angular position as the peaks of high Tc phase were observed in the precursor. After pyrolysis at $400^{\circ}C$ and calcination at $840^{\circ}C$ for 4h. the (001)peak of the high Tc phase was cleary observed. Experimental results suggest that the intermediate phase formed before the formation of the superconducting phase may be the most important factor in determining whether it is easy to form the high Tc phase or not. because the nucleation barriers of the two superconducting phase may be altered by the variation of the crystal structures of those intermediate phase.

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Fabrication of High Tc Superconductor Using Thermal Pyrolysis (열분해법에 의한 고온 초전도 합성)

  • Lee, Sang-Heon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.85-86
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    • 2006
  • A high Tc superconducting with a nominal composition of $Bi_2Sr_2Ca_2Cu_3O_y$ was prepared by the citarte method. The solid precursor produced by the dehydration of the gel at $120^{\circ}C$ for 12h is not in the amorphous state as expected but in a crystalline state. X-ray diffraction peaks of nearly the same angular position as the peaks of high Tc phase were observed in the precursor. After pyrolysis at $400^{\circ}C$ and calcination at $840^{\circ}C$ for 4h, the (001)peak of the high Tc phase was cleary observed. Experimental results suggest that the intermediate phase formed before the formation of the superconducting phase may be the most important factro in determining whether it is easy to form the high Tc phase or not, because the nucleation barriers of the two superconducting phase may be altered by the variation of the crystal structures of those intermediate phase.

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Effects of RTA on the Properties of SBNO Thin Film (SBNO 박막의 특성에 미치는 RTA 영향)

  • Kim, Jin-Sa
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.11
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    • pp.926-929
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    • 2012
  • The $Sr_{0.7}Bi-{2.3}Nb_2O_9$(SBNO) thin films were deposited on Si substrate by RF magnetron sputtering method at $300^{\circ}C$ of substrate temperature. And the SBNO thin films were annealed at $650{\sim}800^{\circ}C$ using RTA (rapid thermal annealing). The grain of SBNO thin films were increased with the increase of annealing temperature. The dielectric constant (100) of SBNO thin film was obtained by RTA above $750^{\circ}C$. The voltage dependence of dielectric loss showed a value within 0.03 in voltage ranges of -5~+5 V. Also, the dielectric constant characteristics showed a stable value with the increase of frequency.

Consideration on the Type and Structure of the Capital City in the Liáo(遼) Dynasty (요대(遼代) 도성(都城)의 유형과 형태구조에 대한 고찰)

  • Dong, Xinlin
    • Korean Journal of Heritage: History & Science
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    • v.45 no.3
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    • pp.4-27
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    • 2012
  • The five capital(五京) was installed in the $Li{\acute{a}}o$(遼) Dynasty. $Sh{\acute{a}}ngj{\bar{i}}ng$(上京) was the main capital city of the $Li{\acute{a}}o$(遼) Dynasty. $Zh{\bar{o}}ngj{\bar{i}}ng$(中京) was the second capital(陪都); and the other three was the capital city with symbolic meaning. The layout of $Sh{\grave{a}}ngj{\bar{i}}ng$ was the '日-shaped plan; this was newly advent structure of ancient Chinese capital city system. $Zh{\bar{o}}ngj{\bar{i}}ng$(中京) was surrounded by multiple ramparts influenced by the $Bi{\grave{a}}nli{\acute{a}}ng$ Fortress (?梁城). Three capitals, Nanjing(南京), $X{\bar{i}}j{\bar{i}}ng$(西京) and $D{\bar{o}}ngj{\bar{i}}ng$(東京), were reconstructed on the foundation of the previously constructed town in $T{\acute{a}}ng$(唐) or Bohai(渤海) Fortress (舊城). The structure and Planning of $Sh{\grave{a}}ngj{\bar{i}}ng$(上京) in the $Li{\acute{a}}o$(遼) Dynasty, had significantly influenced in the capital city planning of the $J\bar{i}n$(金), $Yu{\acute{a}}n$(元) and Qing(淸) Dynasties of China

Basic characteristics of metal-ferroelectric-insulator-semiconductor structure using a high-k PrOx insulator layer

  • Noda, Minoru;Kodama, Kazushi;Kitai, Satoshi;Takahashi, Mitsue;Kanashima, Takeshi;Okuyama, Masanori
    • Electrical & Electronic Materials
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    • v.16 no.9
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    • pp.64.1-64
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    • 2003
  • A metal-ferroelectric [SrBi$_2$Ta$_2$O$\_$9/ (SBT)-high-k-insulator(PrOx)-semiconductor(Si) structure has been fabricated and evaluated as a key part of metal-ferroelectric-insulator-semiconductor-field-effect-transistor MFIS-FET memory, aiming to improve the memory retention characteristics by increasing the dielectric constant in the insulator layer and suppressing the depolarization field in the SBT layer. A 20-nm PrOx film grown on Si(100) showed both a high of about 12 and a low leakage current density of less than 1${\times}$ 10e-8 A/$\textrm{cm}^2$ at 105 MV/cm. A 400-nm SBT film prepared on PrOx/Si shows a preferentially oriented (105) crystalline structure, grain size of about 130 nm and subface roughness of 3.2 nm. A capacitance-voltage hysteresis is confirmed on the Pt/SBT/PrOx/Si diode with a memory window of 0.3V at a sweep voltage width of 12 V. The memory retention time was about 1 104s, comparable to the conventional Pt/SBT/SiO$\_$x/N$\_$y/(SiO$\_$N/)/Si. The gradual change of the capacitance indicates that some memory degradation mechanism is different from that in the Pt/SBT/SiON/Si structure.

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Fabrication and Electrical Properties of PZT/BFO Multilayer Thin Films

  • Jo, Seo-Hyeon;Nam, Sung-Pil;Lee, Sung-Gap;Lee, Seung-Hwan;Lee, Young-Hie;Kim, Young-Gon
    • Transactions on Electrical and Electronic Materials
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    • v.12 no.5
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    • pp.193-196
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    • 2011
  • Lead zirconate titanate (PZT)/ bismuth ferrite (BFO) multilayer thin films have been fabricated by the spin-coating method on Pt(200 nm)/Ti(10 nm)/$SiO_2$(100 nm)/p-Si(100) substrates using $BiFeO_3$ and $Pb(Zr_{0.52}Ti_{0.48})O_3$ metal alkoxide solutions. The PZT/BFO multilayer thin films show a uniform and void-free grain structure, and the grain size is smaller than that of PZT single films. The reason for this is assumed to be that the lower BFO layers play an important role as a nucleation site or seed layer for the formation of homogeneous and uniform upper PZT layers. The dielectric constant and dielectric losses decreased with increasing number of coatings, and the six-layer PZT/BFO thin film has good properties of 162 (dielectric constant) and 0.017 (dielectric losses) at 1 kHz. The remnant polarization and coercive field of three-layer PZT/BFO thin films were 13.86 ${\mu}C/cm^2$ and 37 kV/cm respectively.

Decontamination of Interior of Field Tent Employed Geobacillus stearothermophilus Spores using a Hydrogen Peroxide Vapor System (과산화수소증기 시스템을 이용한 야전용 천막 내 Geobacillus stearothermophilus 아포 제독)

  • Yoon, Sung Nyo;Kim, Yun Ki;Jeung, Jeung Hoon;Yoo, Hyun Sang;Min, Kyung Yool;Kim, Min Cheol;Kim, Se Kye;Ryu, Sam Gon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.19 no.5
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    • pp.669-674
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    • 2016
  • The purpose of this study is to demonstrate the suitability of hydrogen peroxide($H_2O_2$) vapor system for platform interior decontamination. Geobacillus stearothermophilus biological indicator(BI) strips and a field tent were used as a biological simulant and as a simulated platform, respectively. Decontamination was performed based on injection rates and tent sizes with exposure time 60 minutes. We standardized the conditions for the field tent decontamination : 8.0 g/min for $30m^3$($H_2O_2$ vapor concentration of 150~500 ppm, relative humidity of 50 %) and 12.0 g/min for $60m^3$($H_2O_2$ vapor concentration of 250~400 ppm, relative humidity of 55 %). Thus we suggest the system is one of the possible candidates for decontamination of platform interiors.

A Study on Neutron Resonance Energy of 180Ta below 1eV Energy (1 eV 이하 에너지 영역에서의 180Ta 동위원소의 중성자공명에 대한 연구)

  • Lee, Samyol
    • Journal of the Korean Society of Radiology
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    • v.8 no.6
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    • pp.287-292
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    • 2014
  • In this study, the neutron capture cross section of $^{180}Ta$(natural existence ratio: 0.012 %) obtain by measuring has been compared with the evaluated data for the capture data. In generally, the neutron capture resonance is defined as Breit-Wigner formula. The formula consists of the resonance parameters such as neutron width, total width and neutron width. However in the case of $^{180}Ta$, these are very poor experimental neutron capture cross section data and resonance information in below 10 eV. Therefore, in the study, we analyzed the neutron resonance of $^{180}Ta$ with the measuring the prompt gamma-ray from the sample. And the resonance was compared with the evaluated data by Mughabghab, ENDF/B-VII, JEFF-3.1 and TENDL 2012. Neutron sources from photonuclear reaction with 46-MeV electron linear accelerator at Research Reactor Institute, Kyoto University used for cross section measurement of $^{180}Ta(n,{\gamma})^{181}Ta$ reaction. $BGO(Bi_4Ge_3O_{12})$ scintillation detectors used for measurement of the prompt gamma ray from the $^{180}Ta(n,{\gamma})^{181}Ta$ reaction. The BGO spectrometer was composed geometrically as total energy absorption detector.

Physical and Sensory Characteristics of Korean Style Meat Products (한국형 육가공 제품류의 물리적 및 관능적 품질 특성)

  • Kim, I.S.;Jin, S.K.;Hah, K.H.;Lyou, H.J.;Park, K.H.
    • Journal of Animal Science and Technology
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    • v.47 no.1
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    • pp.49-56
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    • 2005
  • The Korean styled meat products such as grilled and/or roasted ham(Jikhwagui: J), Bulgogi ham(B), Kimbab ham(K) and sliced roasted ham(DDukgalbi: D) were obtained from different Korean meat processing companies and investigated for their salinity, saccharinity, pH, moisture and fat content, meat color and sensory evaluation. The results obtained were as follows; Percentage of saccharinity in J, B, K and D ranged 7.5 %(13) - 12.7% (J2), 5.3 0/«B2) -7.5 o/«BI), 5.2 0/«K4) - 6.6 o/«KI, K2, KS), and 6.60/«04) - 14.4o/«Dl), respectively. Percentage of salinity in J, B, K and D ranged 2.260/«13)- 2.38 0/«J4), 1.850/«B2) - 2.45 0/«B3), 1.94o/«KI) - 2.40% (K3), and 1.830/«02) - 2.19 o/«Dl), respectively. The pH value of J, B and K were ranged 6.30 - 6.44, 6.266.37 and 6.20 - 6.42, respectively, which are slightly higher than that of D(5.86 - 6.25). Content of average moisture were higher in B(61.0 %), K(59.94%) and J(59.63%) compared to the D(55.93%). In crude fat, B and D were ranged 14-21 %, which are very lower than those of K(59.94%) and J(59.63%). In meat color, $L^*$ value were above 50.0, except D2 and D3. $a^*$ value of B were slightly higher than those of other meat products. Compared to sensory evaluation, the overall acceptability of J is excellent in the range of saccharinity 12.7%, salinity 2.3 %, moisture 61 %, crude fat II - 12%, $L^*$ value 52 - 54, and $a^*$ value 12.3- 12.7. In the case of B, the overall acceptability is excellent in the range of saccharinity 6.6 - 7.5 %, salinity 1.90- 2.45 %, moisture 60 %, crude fat 15 %, $L^*$ value 56, and $a^*$ value 15. In the case of K, the overall acceptability is excellent in the range of saccharinity 6.5 %, salinity 2.4 %, moisture 61 %, crude fat 16%, $L^*$ value 53, and $a^*$ valuce 15. In the case of D, the overall acceptability is excellent in the range of saccharinity 14.0%, salinity 2.1 %, moisture 55%, crude fat 55%, $L^*$ value 50, and $a^*$ value 13.