• Title/Summary/Keyword: Pt film

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Structure evolution of Pt doped amorphous $V_{2}O_{5}$ cathode film for thin film battery (Pt이 도핑된 박막 전지용 비정질 산화바나듐 박막의 구조적 변화)

  • 김한기;전은정;옥영우;성태연;조원일;윤영수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.889-892
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    • 2000
  • We have investigated the Pt doping effect on structural and electrochemical properties of amorphous vanadium oxide film, grown by radio frequency magnetron sputtering. Room temperature charge-discharge measurements based on a half-cell with a constant current clearly indicated that the Pt doping could improve the cyclibility of V$_2$O$_{5}$ cathode film. Using glancing angle x-ray diffraction (GXRD) and high resolution transmission electron microscopy (HRTEM) analysis, we found that the Pt doping with l0W r.f. power induce more random amorphous structure than undoped V$_2$O$_{5}$ film. As the r.f. power of Pt increases, large amount of Pt incorporates into amorphous V$_2$O$_{5}$ and makes PtOx microcrystalline phase in amorphous matrix. This result suggests that the semicondcuting PtOx microcrystalline phase in amorphous matrix lead to a drastically faded cyclibility of 50W Pt doped V$_2$O$_{5}$ cathode film. Possible explanations are given to describe the Pt doping effect on cyclibility of vanadium oxide cathode film.de film.

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Improvement of Magnetic Properties and Texture of FePt Thin Films on MgO Substrates by Sn Addition

  • Chun, Dong-Won;Kim, Sung-Man;Kim, Gyeung-Ho;Jeung, Won-Young
    • Journal of Magnetics
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    • v.14 no.1
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    • pp.7-10
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    • 2009
  • In this work, we studied the effects of Sn addition on the ordering temperature of FePt thin film. The coercivity of FePtSn film was about 1000 Oe greater than the coercivity of FePt film for an annealing temperature of $600^{\circ}C$. Therefore, Sn addition was effective in promoting the $L1_0$ ordering and in reducing the ordering temperature of the FePt film. From our X-ray diffraction results, we found that in the as-deposited film, the addition of Sn induced a lattice expansion in disordered FePt thin films. After the annealing process, the excess Sn diffuses out from the ordered FePt thin film because of the difference in the solid solubility of Sn between the disordered and ordered phases. The existence of precipitates of Sn from the FePt lattice was deduced by Curie temperature measurements of the FePt and FePtSn films. Therefore, the key role played by the addition of Sn to the FePt film can be explained by a reduction in the activation energy for the $L1_0$ order-disorder transformation of FePt which originates from the high internal stress in the disordered phase induced by the supersaturated Sn atoms.

Fabrication of Pt Thin-film Type Microheater for Thermal Microsensors and Its Characteristics (열형 마이크로센서용 백금박막형 미세발열체의 제작과 그 특성)

  • 정귀상;홍석우
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.6
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    • pp.509-513
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    • 2000
  • The physical and electrical characteristics of MgO and Pt thin-films on it deposited by reactive sputtering and rf magnetron sputtering respectively were analyzed with annealing temperature and time by four point probe SEM and XRD. Under annealing conditions of 100$0^{\circ}C$ and 2 hr, MgO thin-film had the properties of improving Pt adhesion to SiO$_2$and insulation without chemical reaction to Pt thin-film and the sheet resistivity and the resistivity of Pt thin-film deposited on it were 0.1288 Ω/ and 12.88 $\mu$$\Omega$.cm respectively. We made Pt resistance pattern on SiO$_2$/Si substrate by life-off method and fabricated Pt thin-film type microheater for thermal microsensors by Pt-wire Pt-paste and SOG(spin-on-glass). In the temperature range of 25~40$0^{\circ}C$ we estimated TCR(temperature coefficient of resistance) and resistance ratio of thin-film type Pt-RTD(resistance thermometer device). We obtained TCR value of 3927 ppm/$^{\circ}C$ close to the bulk Pt value. Resistance values were varied linearly within the range of the measurement temperature. The thermal characteristics of fabricated thin-films type Pt micorheater were analyzed with Pt-RTD integrated on the same substrate. The heating temperature of Pt microheater could be up to 40$0^{\circ}C$ with 1.5 watts of the heating power.

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CO Sensing Characteristics of $Pt-SnO_{2-x}$ Thin Film Devices Fabricated by Thermal Oxidation (열산화법으로 형성한 $Pt-SnO_{2-x}$ 박막소자의 CO 가스 감지특성)

  • Shim, Chang-Hyun;Park, Hyo-Derk;Lee, Jae-Hyun;Lee, Duk-Dong
    • Journal of Sensor Science and Technology
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    • v.1 no.2
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    • pp.117-123
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    • 1992
  • $Pt-SnO_{2-x}$ thin film sensing devices has been fabricated by thermal oxidation of stacked Pt-Sn thin film on the heater. The thickness of Sn thin film deposited by thermal evaporation was $4000{\AA}$ and the thickness of Pt deposited by D. C. sputtering on Sn thin film was $14{\sim}71{\AA}$ range. The XRD analysis show that the $Pt-SnO_{2-x}$ thin films are formed by grains with a diameter of about $200{\AA}$ randomly connected and the crystalline phase of the thin films are preferentally oriented in the (110) direction. $Pt-SnO_{2-x}$ thin film device (Pt thickness : $43{\AA}$) to 6000 ppm CO shows the sensitivity of 80% and high selectivity to CO. And the operating temperature and the thermal oxidation temperature of $Pt-SnO_{2-x}$ thin film device with high sensitivity to CO were $200^{\circ}C$ and $500^{\circ}C$, respectively.

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Pt Doping Mechanism of Vanadium Oxide Cathode Film Grown on ITO Glass for Thin Film Battery

  • Kim, Han-Ki;Seong, Tae-Yeon;Jeon, Eun-Jeong;Cho, Won-Il;Yoon, Young-Soo
    • Journal of the Korean Ceramic Society
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    • v.38 no.1
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    • pp.100-105
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    • 2001
  • An all solid-state thin film battery (TFB) was fabricated by growing, undoped and Pt-doped vanadium oxide cathode film ( $V_2$ $O_{5}$ ) on I $n_2$ $O_3$: Sn coated glass, respectively. Room temperature charge-discharge measurements based on Li/Lipon/ $V_2$ $O_{5}$ full-cell structure with a constant current clearly shows that the Pt-doped $V_2$ $O_{5}$ cathode film is superior, in terms of cyclibility. X-ray diffraction (XRD) results indicate that the Pt doping process induces a more random amorphous structure than an undoped $V_2$ $O_{5}$ film. In addition to its modified structure, the Pt-doped $V_2$ $O_{5}$ film has a smoother surface than the undoped sample. Compared to an undoped $V_2$ $O_{5}$ film, the Pt doped $V_2$ $O_{5}$ cathode film has a higher electron conductivity. We hypothesize that the addition of Pt alters electrochemical performance in a manner of making more random amorphous structure and gives an excess electron by replacing the $V^{+5}$. Possible mechanisms are discussed for the observed Pt doping effect on structural and electrochemical properties of vanadium oxide cathode films, which are grown on I $n_2$ $O_3$: Sn coated glass.

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The Effects of Deposition Temperature of Pt Top Electrodes on the Electrical Properties of PZT Thin Films (Pt 상부 전극 증착온도가 PZR 박막의 전지적 특성에 미치는 영향)

  • Lee, Kang-Woon;Lee, Won-Jong
    • Korean Journal of Materials Research
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    • v.8 no.11
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    • pp.1048-1054
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    • 1998
  • The effects of deposition temperature of Pt top electrodes on the electrical properties of Pb(Zr,Ti))$O_3$, (PZT) thin film were investigated. When the Pt top electrodes were deposited at substrate temperatures of $200^{\circ}C$ or above,the ferroelectric properties of the PZT thin film under the Pt electrode were severely degraded. Whereas those of the PZT film where the Pt electrodes were not deposited were not degraded. Water vapors which remained in the vacuum chamber were dissociated into hydrogen atoms by the catalysis of Pt top electrode, and those hydrogen atoms diffused into the PZT film and produced oxygen vacancies at high substrate temperature, resulting in the degradation of the ferroelectric properties of the PZT film located under the Pt electrode. Since the water vapors could not be dissociated into hydrogen atoms without the catalysis of Pt. the degradation of the PZT film did not take place where the Pt electrode were not deposited. The degraded feroelectric properties could be recovered by rapid thermal annealing (RTA) treatment. On the other hand. leakage current characteristics were improved with increasing the deposition temperature of Pt top electrodes.

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Structure Evolution of Pt doped Amorphous ${V_2}{O_5}$Cathode Film for Thin Film Battery (박막 전지용 Pt 도핑 비정질 산화바나듐의 구조적 변화)

  • 김한기;전은정;옥영우;성태연;조원일;윤영수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.9
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    • pp.751-757
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    • 2000
  • The r.f. power effect for Pt doping is investigated on structural and electrochemical properties of amorphous vanadium oxide(V$_2$O$_{5}$) film, grown by direct current (d.c.) magnetron sputtering. Room temperature charge-discharge measurements based on a half-cell with a constant current clearly indicated that the Pt doping could improve the cyclibility of V$_2$O$_{5}$ cathode film. Using glancing angle x-ray diffraction(GXRD) and high-resolution transmission electron microscopy (HRTEM) analysis, we found that the Pt doping with 10W r.f. power induces more random amorphous structure than undoped V$_2$O$_{5}$ film. As the r.f. power of Pt target increases. large amount of Pt atoms incorporates into the amorphous V$_2$O$_{5}$ film and makes $\alpha$-PtO$_2$microcrystalline phase in the amorphous V$_2$O$_{5}$ matrix. These results suggest that the semiconducting $\alpha$-PtO$_2$ microcrystalline phase in amorphous matrix lead to a drastically faded cyclibility of 50W Pt doped V$_2$O$_{5}$ cathode film. Possible explanations are given to describe the Pt doping effect on cyclibillity of the amorphous V$_2$O$_{5}$ cathode film battery. film battery.

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Effect of Nano Buffer Layer on Property and Growth of Carbon Thin Film (탄소계 박막의 성장과 특성에 대한 나노 Buffer Layer의 영향)

  • ;Takashi lkuno;Kenjirou Oura
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.1
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    • pp.53-59
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    • 2003
  • Using Platinum-silicide (PtSi) formed between silicon substrate and carbon film, we have improved the field emission of electrons from carbon films. Pt films were deposited on n-Si(100) substrates at room temperature by DC sputter technique. After deposition, these PtSi thin films were annealed at 400 ~ $600^{\circ}C$ in a vacuum chamber, and the carbon films were deposited on those Pt/Si substrates by laser ablation at room temperature. The field emission property of C/Pt/Si system is found to be better than that of C/Si system and it is showed that property was improved with increasing annealing temperature. The reasons why the field emission from carbon film was improved can be considered as follows, (1)the resistance of carbon films was decreased due to graphitization, (2)electric field concentration effectively occurred because the surface morphology of carbon film deposited on Pt/si substrates with rough surface, (3)it is showed that annealing induced reaction between Pt film and Si substrate, as a consequence that the interfacial resistance between Pt film and Si substrate was decreased.

Fabrication and Characteristics of Hot-Film Type Micro-flowsensors integrated with RTD (측온저항체 온도센서가 집적화된 발열저항체형 마이크로 유량센서의 제작 및 특성)

  • 정귀상;홍석우
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.7
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    • pp.612-616
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    • 2000
  • This paper describes on the fabrication and characteristics of hot-film type micro-flowsensors integrated with Pt-RTD(resistance thermometer device) and micro-heater on the Si membrane in which MgO thin-film was used as medium layer in order to improve adhesion of Pt thin-film to SiO$_2$layer. The MgO layer improved adhesion of Pt thin-film to SiO$_2$layer without any chemical reactions to Pt thin-film under high annealing temperatures. Output voltages increased due to increase of heat-loss from sensor to external. The output voltage was 82 mV at $N_2$flow rate of 2000 sccm/min heating power of 1.2 W. The response time($\tau$:63%) was about 50 msec when input flow was stepinput

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BS/channeling studies on the epitaxially grown Pt(111) films on $Al_2O_3$(0001) (BS/Channeling을 이용한 Pt(111)/$Al_2O_3$(0001) 적층 생장 연구)

  • 이종철;김신철;김효배;정광호;김긍호;최원국;송종환
    • Journal of the Korean Vacuum Society
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    • v.7 no.4
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    • pp.300-305
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    • 1998
  • Crystallinity and structual properties of the epitaxially grown Pt films on $Al_2O_3$(0001) substrate by rf magnetron sputtering at a substrate temperature of $600^{\circ}C$ were studied by using backscattering spectrometry (BS)/channeling and transmission electron microscopy (TEM) measurements. $MeV^4$He ion BS/channeling results showed that the channeling minimum yield of Pt film with a thickness of 3500$\AA$ was 4%. This indicates an excellent crystallinity of Pt film. When the thickness of Pt film was less than 200 $\AA$, the channeling minimum yield of Pt film increased sharply with the decrease in film thickness. The Pt layer on $Al_2O_3$(0001) substrate grew epitaxially to the direction of (111) with six-fold symmetry. Cross-sectional TEM images also showed that Pt film on $Al_2O_3$(0001) substrate consist of twinned domains to release the strain induced by the lattice mismatch and the surface roughness of the film increased at the twin boundaries where the strain was contcentrated.

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