• Title/Summary/Keyword: V5.2

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Crystallization and Conductivity of $CuO-P_{2}O_{5}-Nb_{2}O_{5}-V_{2}O_{5}$ Glasses ($CuO-P_{2}O_{5}-Nb_{2}O_{5}-V_{2}O_{5}$ 유리의 결정화와 전기전도도)

  • 손명모;이헌수;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.291-294
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    • 2000
  • The crystallization behavior and dc Conductivities of CuO-P$_2$O$_{5}$ -Nb$_2$O$_{5}$ -V$_2$O$_{5}$ glasses prepared by quenching on the copper plate were investigated. The conductivities of the glasses were range from 10$^{-5}$ s.$cm^{-1}$ / at room temperature, but the conductivities of the glass-ceramics were 10$^{-3}$ s.$cm^{-1}$ / increased by 10$^2$order. The crystalline product in the glass-ceramics was CuV$_2$O$_{6}$ . The linear relationship between in($\sigma$T) and T$^{-1}$ suggested that the electrical conduction in the present glass-ceramics would be due to a small polaron hopping mechanism.

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Effect of Heating Rate and $V_2O_5$ Addition on Densification and Electrical Properties of $Pb(Mn_{1/3}Sb_{2/3})O_3-PZT$ Ceramics for Piezoelectirc Transformer (압전변압기용 $Pb(Mn_{1/3}Sb_{2/3})O_3-PZT$ 세라믹스에서 승온속도 및 $V_2O_5$ 첨가가 치밀화 및 전기적 특성에 미치는 영향)

  • 허수정;손준호;손정호;이준형;김정주;정우환;박명식;조상희
    • Journal of the Korean Ceramic Society
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    • v.37 no.4
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    • pp.295-301
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    • 2000
  • The effect of V2O5 addition on the low temperature sintering of Pb(Mn1/3Sb2/3)O3-PZT ceramics, which is known as a prominent material for piezoelectric transformer application was studied, and the densification behavior and piezoelectric characteristics of the samples as a function of heating rate were also examined. V2O5 led the system to liquid phase sintering by forming liquid phase during sintering, which accelerated densification through the particle rearrangement in the early stage of sintering. The liquid phase mostly existed at grain boundaries retarded the evaporation of PbO, while the densification temperature and the weight loss of V2O5-free samples were higher than those of samples with V2O5. Faster heating improved the densification of the samples regardless of V2O5 addition. The low temperature sintering at 100$0^{\circ}C$ was achieved in PMS-PZT ceramics with high density and reasonable dielectric and piezoelectric characteristics. This result revealed optimistic way to the development of multi-layered piezoelectric transformers.

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Preparation and Electrical Properties of Electro-conducting Glasses Containing $\textrm{V}_{2}\textrm{O}_{5}$ ($\textrm{V}_{2}\textrm{O}_{5}$계 전자 전도성 유리의 제조 및 전기적 특성)

  • Kim, Il-Gu;Park, Hui-Chan;Son, Myeong-Mo;Lee, Heon-Su
    • Korean Journal of Materials Research
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    • v.7 no.1
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    • pp.81-88
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    • 1997
  • Vanadate glasses using $B_2O_3$ as a network former and with CuO additive were mainly investigated in relation to electrical properties. Crystalline phases formed by heat-treatment in each composition were examined and dc electrical conductivity changes of the glasses were analyzed. Crystalline phases were identified as $V_3O_5,\;a-CuV_2O_6\;and\;{\beta}-CuV_2O_6$ by XRD analysis. Crystallization degrees of $V_2O_5$ and ${\beta}-CuV_2O_6$ were little changed with heat-treatment time, but those of ${\alpha}u-CuV_2O_6$ were changed sharply with heat-treatment time. The more crystallization of ${\alpha}u-CuV_2O_6$ occurred, the higher electrical conductivity was observed. Electrical conductivities with $10^{-2}~10^{-4}/{\Omega}/cm$ at room temperature(303K) could be obtained by controlling the glass compositions. The electrical conductivities were increased with increasing of $V_20_5$ content and decreasing of alkality($CuO/B_2O_3$). In this study, electron was proved to be charge carrier by seebeck coefficient measurement. Accordingly, the glasses are believed to be n-type semiconductor. Calculated activation energies for the conduction were in the range 0.098-0.124 eV. Electrical conduction mechanism was small polaron hopping without showing variable range hopping in the temperature range $30~200^{\circ}C$.

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Development of environmentally friendly inorganic fluorescent pigments, A3V5O14 (A = K and Rb) and Cs2V4O11: Crystal structure, optical and color properties (친환경 무기 형광 안료 A3V5O14 (A = K and Rb) and Cs2V4O11 개발: 결정구조, 광학적 특성 및 착색 특성)

  • Jeong, Gyu Jin;Kim, Jin Ho;Lee, Younki;Hwang, Jonghee;Toda, Kenji;Bae, Byoungseo;Kim, Sun Woog
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.30 no.2
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    • pp.47-54
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    • 2020
  • To develop the bright-vivid red- and yellow-inorganic fluorescent pigments with high luminescence properties, A3V5O14 (A = K and Rb) and Cs2V4O11 inorganic pigments were synthesized by a water assisted solid state reaction (WASSR) method and a conventional solid state reaction method. Although impurity peaks corresponding to the AVO3 and AV3O8 (A = K, Rb, and Cs) were observed in all samples prepared, the trigonal structure A3V5O14 (A = K and Rb) and orthorhombic structure Cs2V4O11 were successfully obtained as a main phase. These inorganic pigments showed the broad absorption band (under 550 nm) originated from CT transitions of VO4 polyhedron, and the strong broad red- and green-emission bands due to 3T21A1 and 3T11A1 transitions of the [VO4]3- group. The A3V5O14 (A = K and Rb) and Cs2V4O11 pigments showed a bright-vivid red- and yellow-body color, where the a* values of the A3V5O14 (A = K and Rb) were +35.5 and +45.9, respectively, and b* value of Cs2V4O11 pigments was +50.3. The L* values of the A3V5O14 (A = K and Rb) and Cs2V4O11 inorganic pigments were over +45. These results indicate that the A3V5O14 (A = K and Rb) and Cs2V4O11 inorganic pigments could be an attractive candidate as a bright-vivid red- and yellow inorganic pigments.

Crystallization and Electrical Conductivity of $CuO-P_{2}O_{5}-V_{2}O_{5}$ Glass for Solid-state Electrolyte (고체전해질용 $CuO-P_{2}O_{5}-V_{2}O_{5}$유리의 결정화와 전기전도도)

  • 손명모;이헌수;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.1018-1021
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    • 2001
  • 1018-1021 The CuO-P$_2$O$_{5}$ containing P$_2$O$_{5}$ as glass-former were prepared by press-quenching method on the copper plate. By post-heat treatment of these glasses, the CuO-P$_2$O$_{5}$ -V$_2$O$_{5}$ -g1ass ceramics was obtained and the crystallization behavior and dc conductivities were investigovted. The heat-treated glass-ceramics decreased in electrical conductivity by the order of 10$^1$ compared to amorphous glass. The linear relationship between In($\sigma$T) and T$^{-1}$ indicated that electrical conduction in CuO-P$_2$O$_{5}$ -V$_2$O$_{5}$ -gass occurred by a small polaron hopping.

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The Effect of $V_2O_5$ Addition on the Microwave Dielectric Properties of $Zn_3Nb_2O_8$ Ceramics ($V_2O_5$ 첨가가 $Zn_3Nb_2O_8$ 마이크로파 유전체 특성에 미치는 영향)

  • Yun, Ho-Byung;Lee, Tae-Kun;Hwang, Yeon
    • Korean Journal of Crystallography
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    • v.17 no.1
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    • pp.24-32
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    • 2006
  • The microwave dielectric properties of $Zn_3Nb_2O_8\;with\;V_2O_5$ addition were investigated. The addition of $V_2O_5$ enhanced the sinterability of $Zn_3Nb_2O_8$, which resulted in high density of $Zn_3Nb_2O_8$ ceramic greater than 95% of the theoretical value when sintered at $900^{\circ}C$ for 4 hours. X-ray diffraction analysis of sintered $Zn_3Nb_2O_8$ ceramic showed no second phase with $V_2O_5$ addition. Dielectric permittivity(${\varepsilon}_r$) and quality factor($Q{\times}f$) varied with both density at different sintering temperature and $V_2O_5$ addition. Dielectric permittivity, quality factor and temperature coefficient($T_{cf}$) of the two mole of $V_2O_5\;added\;Zn_3Nb_2O_8$ that was sintered at $900^{\circ}C$ were 21.4, 40,000, $-54ppm/^{\circ}C$, respectively.

Electrochemical Characteristics of $V_2O_5$ based All Solid State Thin Film Microbattery by Ex-situ Sputtering Method (Ex-situ 스퍼터링법에 의한 $V_2O_5$ 전 고상 박막전지의 전기화학적 특성)

  • Lim Y.C.;Nam S.C.;Jeon E.J.;Yoon Y.S.;Cho W.I.;Cho B.W.;Chun H.S.;Yun K.S.
    • Journal of the Korean Electrochemical Society
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    • v.3 no.1
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    • pp.44-48
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    • 2000
  • Amorphous $V_2O_5$ cathode thin films were prepared by DC-magnetron sputtering at room temperature and the thin film rechargeable lithium batteries were fabricated with the configuration of $V_2O_5/LIPON/Li$ using sequential ex-situ thin film deposition techniques. The electrochemical characteristics of $V_2O_5$ cathode materials Prepared at 80/20 of $Ar/O_2$ ratio showed high capacity and cycling behaviors by half cell test. LIPON solid electrolytes films were prepared by RF-magnetron sputtering using the self-made $Li_3PO_4$ target in pure $N_2$ atmosphere, and it was very stable for lithium contact in the range of 1.2-4.0 V vs. Li. Metallic lithium were deposited on LIPON electrolyte by thermal evaporation methode in dry room. Vanadium oxide based full cell system showed the initial discharge capacity of $150{\mu}A/cm^2{\mu}m$ in the range of $1.2\~3.5V$.

Charge/discharge Properties of $V_2O_5$-AC Composite for Supercapacitor (Supercapacitor용 $V_2O_5$-AC Composite의 충방전 특성)

  • 김명산;김종욱;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.366-369
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    • 1999
  • The purpose of this study is to research and develop V2Os-AC(activated carbon) composite electrode for supercapacitor. Supaercapacitor cell of V2Os-AC composite electrode with 25P70FLiCIO$_{4}$/PC$_{10}$/EC$_{10}$ polymer electrolyte bring out good capacitor Performance below 3V. The discharge capacitance of V2Os-AC(30:70) composite with 70wt.% AC in 1st and 200th cycles was 9.6 and 8.2 F/g at current density of 1m7/cm2. The capacitance of V$_2$O$_{5}$-AC composite with 70wt.% AC capacitor was larger than that of others. The coulombic efficiency of supercapacitor at discharge process of 1 and 200 cycles were 96 and 100%, respectively. V$_2$O$_{5}$-AC composite supercapacitor with 70wt.% AC content showed good capacitance and stability with cycling.ing.ing.

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Humidity Sensitive Properties of $V_2O_5$-added $TiO_2$ Ceramics ($V_2O_5$ 첨가에 따른 $TiO_2$ 세라믹스의 감습특성)

  • Hyun, You-Do
    • Proceedings of the KIEE Conference
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    • 2008.05a
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    • pp.161-163
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    • 2008
  • $TiO_2-V_2O_5$ sol was fabricated using sol-gel method and $TiO_2-V_2O_5$, thin films were fabricated using dip-coating method. $V_2O_5$ sol was added 0.01mole, 0.03mole, 0.05mole into $TiO_2$ sol. Capacitance of thin films decreased with increasing $V_2O_5$ additive and it increased largest at 0.01mole. Because adsorption time and desorption time of thin films was about 2 minutes 40 seconds and about 3 minutes 40 seconds respectively, adsorption time was faster about 1 minutes than desorption time.

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