• Title/Summary/Keyword: SrZrO3

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Effect of Sr/Zr Ratio and Organic Vehicle Addition on Bond Strength of $SrZrO_3 $ Thin Films ($SrZrO_3 $박막의 접착강도에 미치는 Sr/Zr 몰비와 유기화합물 첨가효과)

  • 이세종;이득용;예경환;송요승
    • Progress in Superconductivity and Cryogenics
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    • v.4 no.1
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    • pp.13-16
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    • 2002
  • $SrZrO_3 $resistive oxide barriers on Ag sheathed Bi2223 tapes were prepared by the sol-gel and dip coating method to reduce AC coupling loss. The performance of the dip-coated $SrZrO_3 $ thin films was evaluated in terms of bond strength by varying the Sr/Zr mol ratio and the amount of organic vehicle (ethyl cellulose and a-terpineol) additives. The bond strength of the coatings increased as the Sr/Zr ratio decreased and the amount of organic vehicle rose, respectively. It was found that the effect of organic vehicle addition was more pronounced, suggesting that the adherence of the $SrZrO_3 $ films on Bi2223 tapes was governed primarily by the amount of organic vehicle additive.

Effects of $Mn_2O_3, Y_2O_3$ Additives and Valence State of Mn ion in $Sr(Zr, Ti)O_3$ Microwave Dielectrics ($Sr(Zr, Ti)O_3$ 마이크로파 유전체에 첨가된 $Mn_2O_3, Y_2O_3$ 의 영향과 Mn의 산화상태)

  • 정하균;박도순;박윤창
    • Journal of the Korean Ceramic Society
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    • v.34 no.6
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    • pp.583-590
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    • 1997
  • The effects of Mn2O3 and Y2O3 additives on the microstructure and dielectric properties of Sr(Zr, Ti)O3 have been investigated. Powders with Sr(Zr1-xTix)O3(0$\leq$x$\leq$0.1) composition were prepared by the conventional solid state processing from commercial TiO2 and precipitation-processed ZrO2. The powders containing sintering additives of Mn2O3 and Y2O3 were compacted and then sintered at 1,55$0^{\circ}C$ for 4 h to get>97% relative density. Mn2O3 suppressed the grain growth and Y2O3 enhanced the density of sintered body. The oxidation state of Mn ions were determined by a chemical wet method and EPR spectroscopy. Mn ions were present as Mn2+ and Mn4+ in SrZrO3, while as Mn3+ and Mn4+ in Ti-substituted Sr(Zr, Ti)O3. With the substitution of Ti, the lattice parameters of SrZrO3 decreased and its dielectric constant increased with remarkable decrease in Q value. The dielectric constant of Sr(Zr, Ti)O3 was in the range of 30 to 40, Q values 1,200~5,400 at 6 GHz and temperature coefficient of resonant frequency -67~100 ppm/K.

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GROWTH AND ELECTRICAL PROPERTIES OF (La,Sr)CoO$_3$/Pb(Zr,Ti)O$_3$/(La,Sr)CoO$_3$ HETEROSTRUCTURES FOR FIELD EFFECT TRANSISTOR

  • Lee, J.;Kim, S.W.
    • Journal of the Korean institute of surface engineering
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    • v.29 no.6
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    • pp.839-846
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    • 1996
  • Epitaxial (La, Sr)$CoO_3/Pb(Zr,\;Ti)O_3/(La,\;Sr)CoO_3$by pulsed laser deposition for ferroelectric field effect transistor. Epitaxial $LaCoO_3/Pb(Zr,\;Ti)O_3/(La,\;Sr)CoO_3$ heterostructures exhibited 70$\mu C/cm^2$ and 17 $\mu C/cm^2$at a positively and negatively poled states, respectively. On the other hand, epitaxial (La, Sr)$CoO_3/Pb(Zr,\;Ti)O_3/LaCoO_3$heterostructures show the remnant polarization states opposite to the $LaCoO_3/Pb(Zr,\;Ti)O_3/(La,\;Sr)CoO_3$ heterostructures. This indicates that the interface between (La, Sr)$CoO_3$ (LSCO) and $Pb(Zr, Ti)O_3(PZT)$ layers affects the asymmetric polarization remanence through electrochemical nature. The resistivity of $LaCoO_3$ (LCO) layer was found to be dependent on an ambient oxygen, primarily the ambient oxygen pressure during deposition. The resistivity of the LCO layer varied in the range of 0.1-100 $\Omega$cm. It is suggested that, with an appropriate resistivity of the LCO layer, the LCO/PZT/LSCO heterostructure can be used as the ferroelectric field effect transistor.

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Influence of PVP Content and Drying Condition on Microstructure of SrZrO3 Thin Films (SrZrO3 박막 미세조직에 미치는 PVP 결합제 첨가량 및 건조조건 영향)

  • 이세종;이득용;예경환;송요승
    • Journal of the Korean Ceramic Society
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    • v.40 no.5
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    • pp.501-505
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    • 2003
  • SrZrO$_3$ resistive oxides on Ag tapes were prepared by the sol-gel and dip coating method to investigate the effect of PVP content and drying condition on microstructure of the films. Although the film thickness increased with the addition of PVP, the amount of PVP and heat treatment were not effective to reduction of formation of microcracks at the films. However, lower drying temperature and longer drying time were beneficial to control the microcracks of the SrZrO$_3$ films, indicating that the microcracking of the films was governed primarily by the drying condition.

Resistive Switching Behavior of Cr-Doped SrZrO3 Perovskite Thin Films by Oxygen Pressure Change (산소 분압의 변화에 따른 Cr-Doped SrZrO3 페로브스카이트 박막의 저항변화 특성)

  • Yang, Min-Kyu;Park, Jae-Wan;Lee, Jeon-Kook
    • Korean Journal of Materials Research
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    • v.20 no.5
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    • pp.257-261
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    • 2010
  • A non-volatile resistive random access memory (RRAM) device with a Cr-doped $SrZrO_3/SrRuO_3$ bottom electrode heterostructure was fabricated on $SrTiO_3$ substrates using pulsed laser deposition. During the deposition process, the substrate temperature was $650^{\circ}C$ and the variable ambient oxygen pressure had a range of 50-250 mTorr. The sensitive dependences of the film structure on the processing oxygen pressure are important in controlling the bistable resistive switching of the Cr-doped $SrZrO_3$ film. Therefore, oxygen pressure plays a crucial role in determining electrical properties and film growth characteristics such as various microstructural defects and crystallization. Inside, the microstructure and crystallinity of the Cr-doped $SrZrO_3$ film by oxygen pressure were strong effects on the set, reset switching voltage of the Cr-doped $SrZrO_3$. The bistable switching is related to the defects and controls their number and structure. Therefore, the relation of defects generated and resistive switching behavior by oxygen pressure change will be discussed. We found that deposition conditions and ambient oxygen pressure highly affect the switching behavior. It is suggested that the interface between the top electrode and Cr-doped $SrZrO_3$ perovskite plays an important role in the resistive switching behavior. From I-V characteristics, a typical ON state resistance of $100-200\;{\Omega}$ and a typical OFF state resistance of $1-2\;k{\Omega}$, were observed. These transition metal-doped perovskite thin films can be used for memory device applications due to their high ON/OFF ratio, simple device structure, and non-volatility.

Effect of Co Dopant on the (La, Sr)$MnO_3$ Cathode for Solid Oxide Fuel Cell (고체산화물 연료전지용 (La, Sr)$MnO_3$ 양극에 대한 Co 첨가효과)

  • 김재동;김구대;이기태
    • Journal of the Korean Ceramic Society
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    • v.37 no.6
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    • pp.612-616
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    • 2000
  • The effect of Co dopant on the (La, Sr)MnO3 cathode was investigated. La2Zr2O7 and SrZrO3 were formed as the reaction products between YSZ and LSMC. The reactivity of LSMC with YSZ increased with increasing Co content. However, the cathodic polarization resistance decreased with increasing Co doping. Therefore, doping Co at Mn site in the (La, Sr)MnO3 cathode was effective on controlling the polarization resistance of the cathode. The polarization property of LSMC-YSZ composite(60 wt%: 40 wt%) cathode was better than that of LSMC single cathode.

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Resistive Switching Properties of Cr-Doped SrZrO3 Thin Film on Si Substrate (실리콘 기판위에서의 Cr-Doped SrZrO3 박막의 저항변화 특성)

  • Yang, Min-Kyu;Ko, Tae-Kuk;Park, Jae-Wan;Lee, Jeon-Kook
    • Korean Journal of Materials Research
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    • v.20 no.5
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    • pp.241-245
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    • 2010
  • One of the weak points of the Cr-doped SZO is that until now, it has only been fabricated on perovskite substrates, whereas NiO-ReRAM devices have already been deposited on Si substrates. The fabrication of RAM devices on Si substrates is important for commercialization because conventional electronics are based mainly on silicon materials. Cr-doped ReRAM will find a wide range of applications in embedded systems or conventional memory device manufacturing processes if it can be fabricated on Si substrates. For application of the commercial memory device, Cr-doped $SrZrO_3$ perovskite thin films were deposited on a $SrRuO_3$ bottom electrode/Si(100)substrate using pulsed laser deposition. XRD peaks corresponding to the (112), (004) and (132) planes of both the SZO and SRO were observed with the highest intensity along the (112) direction. The positions of the SZO grains matched those of the SRO grains. A well-controlled interface between the $SrZrO_3$:Cr perovskite and the $SrRuO_3$ bottom electrode were fabricated, so that good resistive switching behavior was observed with an on/off ratio higher than $10^2$. A pulse test showed the switching behavior of the Pt/$SrZrO_3:Cr/SrRuO^3$ device under a pulse of 10 kHz for $10^4$ cycles. The resistive switching memory devices made of the Cr-doped $SrZrO_3$ thin films deposited on Si substrates are expected to be more compatible with conventional Si-based electronics.

Fabrication and Electrical Characteristics of SrZr$_{0.95}$M$_{0.05}$O$_3$-$\delta$ and BaZr$_{0.95}$O$_3$-$\delta$(M=Ga, Y) (SrZr$_{0.95}$M$_{0.05}$O$_3$-$\delta$ 및 BaZr$_{0.95}$O$_3$-$\delta$(M=Ga, Y) 의 제조와 전기적 특성)

  • 편영미;유광수
    • Journal of the Korean Ceramic Society
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    • v.36 no.7
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    • pp.679-684
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    • 1999
  • Specimens of SrZr0.95Ga0.05O3-$\delta$, SrZr0.95Y0.05O3-$\delta$, BaZr0.95Ga0.05O3-$\delta$ and BaZr0.95Y0.05O3-$\delta$ were fabricated by a solid-state reaction method and subsequent sintering at 150$0^{\circ}C$ to 1$600^{\circ}C$ The microstructures and electrical characteristics of the specimens were studied. Only BaZr0.95Ga0.05O3-$\delta$ showed dense microstructure and had typical impedance spectra at various temperature. Its electrical conductivity by impedance analysis was 2.7$\times$10-3$\Omega$-1.cm-1 at 90$0^{\circ}C$ in air. The BaZr0.95Ga0.05O3-$\delta$ exhibited lower grain rsistance in wet atmosphere than in dry atmosphere and the reduction of resistance is due to the proton conduction.

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A study on the preparation of $(Ba_{1-X}Sr_X)ZrO_3$ using oxalate method and its dielectric properties (수산염법에 의한 $(Ba_{1-X}Sr_X)ZrO_3$의 합성 및 그의 유전특성에 관한 연구)

  • Oh Seong Kweon;Nam Seok Baik;Byung Ha Lee
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.4 no.3
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    • pp.252-261
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    • 1994
  • The $(Ba_{1-X}Sr_X)ZrO_3$ powder showing chemically pure and fine particle size was attempted to be synthesized by the oxalate method. The objective of this study is to determine the optimum synthesis condition of stable $(Ba_{1-X}Sr_X)ZrO_3$ powder in terms of the temperatures coefficient of resonant frequency ${\tau}_f$ by examining the microstructure and dielectric properties of the synthesized powder. The six compounds (x=0, 0.2, 0.4, 0.6, 0.8, 1) of $(Ba_{1-X}Sr_X)ZrO_3$ were prepared by the oxalate method, and then calcined at $1000^{\circ}C$ to obtain the crystalline $(Ba_{1-X}Sr_X)ZrO_3$ powder. The synthesized powder showed the globular-shape and average particle size of less than $0.2 \mu\textrm{m}$. The composition of x=0.5, i.e., half of Ba was replaced by Sr, is experted to show the zero value of temperatures coefficient of capacitance ${\tau}_c$.

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Synergistic Effect of Sulfonated Poly(Ether Ether Ketone)/Strontium Zirconate Perovskite Nanofiber-Based Novel Electrospun Composite Membranes for Fuel Cell Applications (연료전지용 술폰화된 폴리(이써 이써 케톤)/스트론튬 지르코네이트 페로브스카이트 나노섬유 기반 신규 전기방사 복합막의 시너지 효과)

  • SELVAKUMAR, KANAKARAJ;KIM, AE RHAN;YOO, DONG JIN
    • Transactions of the Korean hydrogen and new energy society
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    • v.33 no.2
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    • pp.164-175
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    • 2022
  • In this work, sulfonated poly (ether ether ketone) (SPEEK) composite membranes including strontium zirconate (SrZrO3) were fabricated by the electrospinning method. Fourier-transform infrared spectroscopic analysis and X-ray diffraction analysis were used to identify the chemical structure and the crystallinity of SrZrO3 and electrospun composite membranes. The thermal stability of the pure SPEEK and SPEEK/SrZrO3 electrospun composite membranes were investigated by using thermogravimetric analysis. The physicochemical properties and proton conductivity were enhanced with the addition of different weight ratio of SrZrO3 nanofiller (2, 4 and 6 wt%) in SPEEK polymer. The optimized SPEEK/SrZrO3-4 electrospun membrane containing 4 wt% of SrZrO3 showed a high proton conductivity compared to other electrospun SPEEK/SrZrO3 composite membranes. The results indicate that electrospun composite membranes incorporating these perovskite nanofillers should be explored as potential candidates for use in proton exchange membrane fuel cells.