• Title/Summary/Keyword: PdO thin films

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Fabrication of the SnO2 thin-film gas sensors using an R.F. magnetron sputtering method and their alcohol gas-sensing characterization (R.F. Magnetron Sputtering 법을 이용한 SnO2 박막 센서의 제조 및 알콜 감도 특성)

  • Park, Sang-Hyoun;Kang, Ju-Hyun;Yoo, Kwang-Soo
    • Journal of Sensor Science and Technology
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    • v.14 no.2
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    • pp.63-68
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    • 2005
  • The nano-grained Pd or Pt-doped $SnO_{2}$ thin films were deposited on the alumina substrate at ambient temperature or $300^{\circ}C$ by using an R.F. magnetron sputtering system and then annealed at $650^{\cir}C$ for 1 hour or 4 hours in air. The crystallinity and microstructure of the annealed films were analyzed. A grain size of the thin films was 30 nm to 50 nm. As a result of gas sensitivity measurements to an alcohol vapor of $36^{\circ}C$, the 2 wt.% Pt-doped $SnO_{2}$ thin-film sensor deposited at $300^{\circ}C$ and annealed at $650^{\circ}C$ for 4 hours showed the highest sensitivity.

Fabrication and Characteristics of High-performance Doped-$SnO_2$ Thin Films for Explosive Gas Sensor

  • Chwa, Sang-Ok;Park, Hee-Chan;Kim, Kwang-Ho
    • The Korean Journal of Ceramics
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    • v.2 no.2
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    • pp.83-88
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    • 1996
  • Long term stability, sensitization in air, and gas sensing behaviors of tin oxide films were investigated with doping of antimony and palladium. The tin oxide films were prepared on a Corning glass by reactive rf sputtering method and tested for detection of hydrogen gas. Sb-doping improved a long-term stability in the base resistance of $SnO_2$ film sensor. A small amount of Pd doping caused the optimum sensor operating temperature to reduce and also enhanced the gas sensitivity, compared with the undoped $SnO_2$ film. Gas sensitivity depended largely on the film thickness. The important sensitization reactions for sensor operating were $(O_{2ads})+e^-\;{\rightarrow}\;2(O_{ads})^-$ on the surface of $SnO_2$ film at elevated temperature in air and a followed reaction of hydrogen atoms with $(O_{ads})^-$ ions.

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Optical Hydrogen Sensor Based on Gasochromic $RuO_2{\cdot}xH_2O$ Thin Film ($RuO_2{\cdot}xH_2O$ 박막의 가스채색 현상을 이용한 수소검지 광센서)

  • Cheong, Hyeon-Sik;Jo, Hyun-Chol;Kim, Kyung-Moon
    • Transactions of the Korean hydrogen and new energy society
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    • v.16 no.1
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    • pp.9-16
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    • 2005
  • We studied the electrochromic properties of hydrated amorphous ruthenium oxide ($RuO_2{\cdot}xH_2O$) thin films using in-situ Raman spectroscopy during electrochemical charging/discharging cycles. We have found that the principal effect of hydrogen insertion into $RuO_2{\cdot}xH_2O$ is reduction of $Ru^{4+}\;to\;Ru^{3+}$, and not formation of new bonds involving hydrogen. We compared the changes in the Raman spectrum of a gasochromic $Pd/RuO_2{\cdot}xH_2O$ film as it is exposed to hydrogen gas with that of electrochemical hydrogen insertion. We tested the changes in the optical transmission of the $Pd/RuO_2{\cdot}xH_2O$ film when exposed to hydrogen gas.

X-Ray Photoelectron Spectroscopy Studies of Pd Supported MgO/Mg (X-선 광전자분광법을 이용한 MgO/Mg 표면에 증착된 Pd의 분석)

  • Tai, Wei-Sheng;Seo, Hyun-Ook;Kim, Kwang-Dae;Kim, Young-Dok
    • Journal of the Korean Vacuum Society
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    • v.18 no.4
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    • pp.281-287
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    • 2009
  • Pd was deposited on magnesium-oxide-covered magnesium ribon substrate by metal thermal evaporation method in high vacuum. The electronic and chemical properties of Pd samples with different coverages were studied using in-situ X-ray Photoelctron Spectroscopy (XPS) and Field Emission Scanning Electron Microscopy (SEM). For relatively lower amounts of Pd deposited(< 1nm), separate Pd particles could be observed, whereas at higher Pd coverages, Pd thin films caused by agglomeration of Pd nanoparticles was found. The metal support interaction with Pd-support was observed. The Pd atoms on the metal oxide/metal interface were partially negative charged by charge transfer.

The effect of rapid thermal annealing treatment for ferroelectric properties of PZT thin films (RTA를 이용한 후열처리가 PZT 박막의 강유전 특성에 미치는 영향)

  • Ju, Pil-Yeon;Park, Young;Jeong, Kyu-Won;Lim, Dong-Gun;Song, Joon-Tae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.136-139
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    • 1999
  • The post-annealing treatments on RF (Radio Frequency) magnetron sputtered PZI(Pb$\_$1.05/(Zr$\_$0.52/, Ti$\_$0.48/)O$_3$thin films(4000${\AA}$) have been investigated. for a structure of PZT/Pt/Ti/SiO$_2$/Si Crystallization pproperties of PZT films were strongly dependent on RTA(Rapid Thermal Annealing) annealing temperature. We were able to obtain a perovskite structure of PZT at a low temperature of 600$^{\circ}C$. P-E curves of Pd/PZT/Pt capacitor annealed at 700$^{\circ}C$ demonstrate typical hysteresis loops. The measured values of P$\_$r/, E$\_$c/, by post annealed at 700$^{\circ}C$ were 12.1 ${\mu}$C/$\textrm{cm}^2$, 120KV/cm respectively.

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Fabrications of Pd/poly 3C-SiC schottky diodes for hydrogen gas sensor at high temperatures (고온 가스센서용 Pd-다결정 3C-SiC 쇼트키 다이오드 제작)

  • Ahn, Jeong-Hak;Chung, Gwiy-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.78-79
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    • 2008
  • In this paper, poly 3C-SiC thin films were grown on $SiO_2$/Si by atmospheric pressure chemical vapor deposition (APCVD) using HMDS, $H_2$, and Ar gas at $1100^{\circ}C$ for 30 min, respectively. And then, palladium films were deposited on poly 3C-SiC by RF magnetron sputter. Thickness, uniformity, and quality of these samples were performed by SEM. Crystallinity and preferred orientationsof palladium were analyzed by XRD. And Pd/poly 3C-SiC schottky diodes were fabricated and characterized by current-voltage measurements. Its electric current density Js and barrier height voltage were measured as $2\times10^{-3}$ A/$cm^2$, 0.58 eV, respectively. And these devices operated about $350^{\circ}C$. From results, Pd/poly 3C-SiC devices are promising for high temperature hydrogen sensor and applications.

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A study on PZT capacitor on the glass substrate (유리 기판 위에서의 PZT 캐패시터에 관한 연구)

  • Ju, Pil-Yeon;Park, Young;Jeong, Kyu-Won;Song, Joon-Tae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.04b
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    • pp.80-83
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    • 2000
  • The post-annealing treatments on rf magnetron sputtered PZT($Pb_{1.05}(Zr_{0.52},\;Ti_{0.48})O_3$) thin films($4000{\AA}$) have been investigated for a structure of PZT/Pt/Ti/Coming glass(1737). Crystallization properties of PZT films were strongly dependent on RTA(Rapid Thermal Annealing) annealing temperature and time. We were able to obtain a perovskite structure of PZT at $650^{\circ}C$ and 10min. P-E curves of Pd/PZT/Pt capacitor demonstrate typical hysteresis loops. The measured values of $P_r$, $E_c$ were $8.1[{\mu}C/cm^2]$, 95[kV/cm] respectively. Polarization value decrease about 25% after $10^9$ cycles.

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Characteristics of PZT thin film on the g1ass substrate (유리 기판 위에서의 PZT 박막의 특성에 관한 연구)

  • Ju, Pil-Yeon;Jeong, Kyu-Won;Park, Young;Park, Ki-Yeop;Song, Joon-Tae
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1477-1479
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    • 2000
  • The annealing treatments on rf magnetron sputtered PZT($Pb_{1.05}(Zr_{0.52},Ti_{0.48})O_3$) thin films(4000${\AA}$) have been investigated for a structure of PZT/Pt/Ti/ITO coated glass. Crystallization properties of PZT films were strongly dependent on RTA(Rapid Thermal Annealing) annealing temperature and time. We were able to obtain a perovskite structure of PZT at 650$^{\circ}C$ and 10min. P-E curves of Pd/PZT/Pt capacitor demonstrate typical hysteresis loops. The measured values of $P_r$, $E_c$ were 15.8[${\mu}C/cm^2$], 95[kV/cm] respectively. Polarization value decrease about 10% after $10^9$ cycles.

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