• 제목/요약/키워드: Sb doped

검색결과 223건 처리시간 0.039초

Thermoelectric Properties of Half-Heusler ZrNiSn1-xSbx Synthesized by Mechanical Alloying Process and Vacuum Hot Pressing

  • Ur, Soon-Chul
    • 한국분말재료학회지
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    • 제18권5호
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    • pp.401-405
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    • 2011
  • Half-heusler phase ZrNiSn is one of the potential thermoelectric materials for high temperature application. In an attempt to investigate the effect of Sb doping on thermoelectric properties, half-heusler phase $ZrNiSn_{1-x}Sb_x$ ($0{\leq}x{\leq}0.08$) was synthesized by mechanical alloying of stoichiometric elemental powder compositions, and consolidated by vacuum hot pressing. Phase transformations during mechanical alloying and hot consolidation were investigated using XRD. Sb doped ZrNiSn was successfully produced in all doping ranges by vacuum hot pressing using as-milled powders without subsequent annealing. Thermoelectric properties as functions of temperature and Sb contents were evaluated for the hot pressed specimens. Sb doping up to x=0.04 in $ZrNiSn_{1-x}Sb_x$ was shown to be effective on thermoelectric properties and the figure of merit (ZT) was shown to reach to the maximum at x=0.02 in this study.

SnO2가 첨가된 저온소결 (Na,K,Li)(Nb,Sb,Ta)O3계 세라믹스의 유전 및 압전 특성 (Dielectric and Piezoelectric Properties of Low Temperature Sintering (Na,K,Li)(Nb,Sb,Ta)O3 Ceramics Doped with SnO2)

  • 이광민;류주현;이지영
    • 한국전기전자재료학회논문지
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    • 제28권11호
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    • pp.690-693
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    • 2015
  • In this paper, in order to develop excellent Pb-free composition ceramics for ultrasonic sensor. The $SnO_2$-doped ($Na_{0.525}K_{0.443}Li_{0.037})(Nb_{0.883}Sb_{0.08}Ta_{0.037})O_3$)(abbreviated as NKL-NST) ceramics have been synthesized using the ordinary solid state reaction method. The effect of $SnO_2$-doping on their dielectric and piezoelectric properties was investigated. The ceramics doped with 0 wt% $SnO_2$ have the optimum values of piezoelectric constant($d_{33}$), piezoelectric figure of merit($d_{33}.g_{33}$), planar piezoelectric coupling coefficient($k_p$) and density : $d_{33}=195[pC/N]$, $d_{33}.g_{33}=5.62pm^2/N.kp=0.40$, $density=4.436[g/cm^3]$. suitable for duplex ultrasonic sensor application.

Ag첨가에 따른 $Pb(Zr,Ti)O_3-Pb(Mn,W,Sb,Nb)O_3$의 유전 및 압전 특성 (Dielectric and piezoelectric properties of Ag doped $Pb(Zr,Ti)O_3-Pb(Mn,W,Sb,Nb)O_3$ Ceramics)

  • 정현우;임성훈;이은선;전창성;이상렬
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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    • pp.117-120
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    • 2004
  • The dielectric and piezoelectric properties of silver doped $Pb(Zr,Ti)O_3-Pb(Mn,W,Sb,Nb)O_3$ ceramics was examined. By varying the contents of silver(0.0, 0.4, 1.0 mol%), the effect of doped silver on PZT-PMWSN thin film was investigated at various sintering temperature(900, 1000, $1100^{\circ}C$). As increasing silver contents, the relative dielectric constant is increased and sinterbility is enhanced. At the specimen with 0.4 mol% Ag and sintered at $1100^{\circ}C$, electromechanical coupling factor(kp), mechanical quality factor(Qm), dielectric constant(${\varepsilon}r$) and dielectric loss were 0.502, 811, 991, 0.006, respectively. The results show that the PZT-PMWSN/Ag composites have enhanced piezoelectic and dielectric properties and processing condition is improved.

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Spark Plasma Sintering 법으로 제조한 CoSb3 Skutterudite계 열전소재의 n형 첨가제 효과 (Effect of n-type Dopants on CoSb3 Skutterudite Thermoelectrics Sintered by Spark Plasma Sintering)

  • 이재기;최순목;이홍림;서원선
    • 한국재료학회지
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    • 제20권6호
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    • pp.326-330
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    • 2010
  • $CoSb_3$ Skutterudites materials have high potential for thermoelectric application at mid-temperature range because of their superior thermoelectric properties via control of charge carrier density and substitution of foreign atoms. Improvement of thermoelectric properties is expected for the ternary solid solution developed by substitution of foreign atoms having different valances into the $CoSb_3$ matrix. In this study, ternary solid solutions with a stoichiometry of $Co_{1-x}Ni_xSb_3$ x = 0.01, 0.05, 0.1, 0.2, $CoSb_{3-y}Te_y$, y = 0.1, 0.2, 0.3 were prepared by the Spark Plasma Sintering (SPS) system. Before the SPS synthesis, the ingots were synthesized by vacuum induction melting and followed by annealing. For phase analysis X-ray powder diffraction patterns were checked. All the samples were confirmed as single phase; however, with samples that were more doped than the solubility limit some secondary phases were detected. All the samples doped with Ni and Te atoms showed a negative Seebeck coefficient and their electrical conductivities increased with the doping amount up to the solubility limit. For the samples prepared by SPS the maximum value for dimensionless figure of merit reached 0.26, 0.42 for $Co_{0.9}Ni_{0.1}Sb_3$, $CoSb_{2.8}Te_{0.2}$ at 690 K, respectively. These results show that the SPS method is effective in this system and Ni/Te dopants are also effective for increasing thermoelectric properties of this system.

$SrTiO_3$ 세라믹 전극에 의한 광전기 화학변환 (Photoelectrochemical Converision with $SrTiO_3$ Ceramic Electrodes)

  • 윤기현;김태희
    • 한국세라믹학회지
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    • 제22권3호
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    • pp.19-24
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    • 1985
  • The phtoelectrochemical porperties of $Nb_2O_5$, $Sb_2O_3$ and $V_2O_5$ doped and pure $SrTiO_3$ ceramic electodes were investigated. Shapes of I-V and I-λ characteristics of the pure $SrTiO_3$ ceramic electrode are similar to those of SrTiO3 single crystal electorde ; the anodic current strats at -0.9V (vs. Ag/AgCI) in 1 N-NaOH aqueous solution and the photoresponse appears at a wavelength of about 390nm and the quantum efficiency is about 3.5% at wavelength of 390nm under 0.5V vs. Ag/AgCl. Photocurrents of $Nb_2O_5$, $Sb_2O_3$ and $V_2O_5$ doped electrodes and $V_2O_5$ doped ceramic electrode appears at wavelength of 390nm and 500nm respectively.

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Opto-Electrical Study of Sol-Gel Derived Antimony Doped Tin Oxide Films on Glass

  • De, Arijit
    • Transactions on Electrical and Electronic Materials
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    • 제16권1호
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    • pp.5-9
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    • 2015
  • Optical and electrical properties were studied for Antimony doped tin oxide thin films from precursors containing 10, 30, 50, and 70 atom% of Sb deposited on bare sodalime silica, barrier layer coated sodalime silica, and pure silica glass substrates by sol-gel spinning technique. The direct band gaps were found to vary from 3.13~4.12 eV when measured in the hv range of 2.5~5.0 eV, and varied from 4.22~5.08 eV when measured in the range of 4.0~7.0 eV. Indirect band gap values were in the range of 2.35~3.11 eV. Blue shift of band gap with respect to bulk band gap and Moss-Burstein shift were observed. Physical thickness of the films decreased with the increase in % Sb. Resistivity of the films deposited on SLS substrate was in the order of $10^{-2}$ ohm cm. Sheet resistance of the films deposited on barrier layer coated soda lime silica glass substrate was found to be relatively less.

Selenide Glass Optical Fiber Doped with $Pr^{3+}$ for U-Band Optical Amplifier

  • Chung, Woon-Jin;Seo, Hong-Seok;Park, Bong-Je;Ahn, Joon-Tae;Choi, Yong-Gyu
    • ETRI Journal
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    • 제27권4호
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    • pp.411-417
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    • 2005
  • $Pr^{3+}-doped$ selenide glass optical fiber, which guarantees single-mode propagation of above at least 1310 nm, has been successfully fabricated using a Ge-Ga-Sb-Se glass system. Thermal properties such as glass transition temperature and viscosity of the glasses have been analyzed to find optimum conditions for fiber drawing. Attenuation loss incorporating the effects of an electronic band gap transition, Rayleigh scattering, and multiphonon absorption has also been theoretically estimated for the Ge-Ga-Sb-Se fiber. A conventional double crucible technique has been applied to fabricate the selenide fiber. The background loss of the fiber was estimated to be approximately 0.64 dB/m at 1650 nm, which can be considered fairly good. When excited at approximately 1470 nm, $Pr^{3+}-doped$ selenide fiber resulted in amplified spontaneous emission and saturation behavior with increasing pump power in a U-band wavelength range of 1625 to 1675 nm.

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