• Title/Summary/Keyword: MoO3

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Studies on the Molybdenum Complexes with Tridentate Schiff Base Ligand (I) (세자리 Schiff Base 리간드의 몰리브덴 착물에 관하여 (제1보))

  • Ki Hyung Chjo
    • Journal of the Korean Chemical Society
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    • v.17 no.3
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    • pp.169-173
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    • 1973
  • The tridentate schiff base ligand, salicyliden amino-o-hydroxy benzene, has derived from salicylaldehyde and o-amino phenol. This ligand reacts with a series of Mo (VI), Mo (V), Mo (IV), and Mo (III) oxidated states and forms a new complexes; [Mo O$_2(H_2O)\;(C_{13}H_9O_2N)]$, [MoO Cl$(H_2O)\;(C_{13}H_9O_2N)]$, [Mo(SCN)$_2(H_2O)\;(C_{13}H_9O2_N)]$$[Mo(H_2O)_2\;(C_{13}H_9O_2N)]_2O$. The Mo (VI), Mo(V) and Mo(Ⅳ) ions in these complexes are octahedron, hexa coordinate, and the mole ratio of these ions to the ligand are 1 : 1, but Mo (III) Complex is a Mo-O-Mo oxygen bridge bond and polynuclear, and the mole ratio of Mo (III) to the ligand 1 : 1 above facts are identified from the data of Infrared spectra, visible spectra, and elemental analysis.

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Effect of Alumina on the Ion-Exchange Capacity of Porous Glasses (다공질유리의 이온교환성에 미치는 알루미나의 영향)

  • 김병호;이덕열;김성길
    • Journal of the Korean Ceramic Society
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    • v.25 no.3
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    • pp.251-260
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    • 1988
  • Ion-exchange porous glasses were prepared by heat treatment and subsequently hydro thermalor acid leaching treatment $10Li_2O$.$(90-x)B_2O_3$.$xSiO_2$ base glasses containing various amount of $Al_2O_3$ or $MoO_3$. It was investigated how the phase separation and the cation exchange capacity(CEC) were affected by the addition of $Al_2O_3$ or $MoO_3$. The optimum condition of phase separation in these glasses was about 48$0^{\circ}C$ for 10 hrs. The degree of phase separation was rapidly suppressed by the addition of $Al_2O_3$ up to 10 mol% and thereafter suppression effect was decreased. The maximum value of CEC, about 252meq/100g, was observed with the $1OLi_2O$.$45B_2O_3$.$45SiO_2+7.5Al_2O_3$ porous glass prepared by hydrothermal treatment and its mean pore radius was about 16.3A. The addition of $MoO_3$ accelerated phase separation and leaching rate. Looking at the remakable increment of pore diameter and pore volume of these porous glasses by the addition of $MoO_3$, the effect of $MoO_3$ may be ascribed to the lowering of silica concentration in the borate phase and to the forming of water-soluble complex with silica during the leaching treatment.

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Annealing Effects of The Electrochromic $MoO_3$ Thin Films (전기변색 $MoO_3$ 박막의 열처리 효과)

  • 임동규;이진민;조봉희;김동진;김영호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.505-508
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    • 1999
  • The effect of the heat treatment on electrochromic properties of $MoO_3$ thin films is investigated by studing optical modulation, optical density, response time, and cyclic voltammetry. From the results of XRD analysis, heat-treated at $450^{\circ}C$ in air for 1 hour $MoO_3$ thin films are found to be crystalline while as-deposited film and heat-treated at low temperature (${\leq}300^{\circ}C$) are amorphous. The electrochrornic devices using as-deposited $MoO_3$ films exhibits good electrochromic properties compare to those using the heat treated $MoO_3$ films. It has shown that the heat-treatment affected the stability and the electrochromic properties of $MoO_3$ films.

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Preparation of Conductive SrMoO3 Thin Films by RF Magnetron Sputtering and Evaluation of Their Electrical Conduction Properties (RF 마그네트론 스퍼터법을 사용한 전도성 SrMoO3 박막 제조 및 전기전도특성 평가)

  • Ryu, Hee-Uk;Sun, Ho-Jung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.6
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    • pp.468-472
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    • 2011
  • Conductive $SrMoO_3$ thin films were fabricated by RF magnetron sputtering with the powder-type sputtering target, and annealed for crystallization. When RTP (rapid thermal processing) in vacuum was applied, the fabricated thin films showed the mixed phases of $SrMoO_3$ and $SrMoO_4$, but $SrMoO_3$ phase could be promoted by the lowering of the working pressure during deposition. In order to eliminate $O_2$ gas during deposition and annealing, further lowering of the working pressure and furnace annealing in hydrogen atmosphere were tried. With the optimization of the deposition and annealing conditions, the thin film with nearly single-phase of $SrMoO_3$ was obtained, and it showed good electrical conduction properties with a low resistivity of $2.5{\times}10^{-3}{\Omega}{\cdot}cm$ at room temperature.

Studies on the Molybdenum Complexes (Molybdenum 錯物에 關한 硏究 (I))

  • Oh, Sang-Oh
    • Journal of the Korean Chemical Society
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    • v.12 no.3
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    • pp.93-98
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    • 1968
  • A series of Molybdenum thiocyanate complex has been prepared as new compound: $MoO_2(CNS)_2Py$, $MoO(CNS)_4Py$, $MoO_2(CNS){\cdot}3Py$, $MoO(CNS)_3{\cdot}2NH_3{\cdot}MoO(CNS)_3{\cdot}2HCONH_2$, where Py = Pyridine. Properties and configuration of the complexes were studied by chemical and physical method.

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Phase Cooperation Between Mo-V-O and Metal Oxide in Selective Oxidation of Acrolein (아크롤레인 선택 산화반응에서 Mo-V-O와 금속산화물의 상간협동)

  • Park, D.W.;Na, S.E.;Kim, K.H.;Lee, W.H.;Chung, J.S.
    • Applied Chemistry for Engineering
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    • v.5 no.2
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    • pp.327-336
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    • 1994
  • The synergistic effects in mechanical mixture catalysts of Mo-V-O and metal oxide were investigated for the selective oxidation of acrolein. The metal oxides used are $SnO_2$, ${\alpha}-Sb_2O_4$, $WO_3$, ${\alpha}-Al_2O_3$, CuO, $MnO_2$, $Cu_2O$, MgO, CoO, and ZnO. Mechanical mixtures of Mo-V-O plus $SnO_2$ or ${\alpha}-Sb_2O_4$ had resulted in higher conversion of acrolein and higher yield of acrylic acid than Mo-V-O. The origin of the synergy is attributed to the cooperation of Mo-V-O and $SnO_2$ or ${\alpha}-Sb_2O_4$, in which $SnO_2$ or ${\alpha}-Sb_2O_4$ forms dissociated oxygens at their oxygen vacancies and transports them to Mo-V-O. $Cu_2O$, MgO, CuO, and $MnO_2$, increased conversion of acrolein but decreased yield of acrylic acid. CoO and ZnO inhibited the catalytic performance of Mo-V-O. The different role of these metal oxides is explained in terms of their oxidation-reduction properties.

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The Sintering Behavior of Ba(Cu, Mo)O3 Flux Added (Ba, Sr)TiO3 Ceramic Dielectrics (Ba(Cu, Mo)O3 Flux가 첨가된 (Ba,Sr)TiO3계 유전체의 소결)

  • 안진용
    • Journal of the Microelectronics and Packaging Society
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    • v.3 no.1
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    • pp.25-32
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    • 1996
  • 본 연구에서는 BaTiO3에 Sr과 Pb를 치환시켜TiO3 조성의 세라믹 유전체를 제조한 후 페로브스카이트형 Ba(Cu, Mo)O3를 저융점 flux 로 첨가하여 120$0^{\circ}C$ 이하의 여러온도에 서 소결을 행하였으며 flux 첨가량의 변화에 따른 소결거동 및 유전 특성의변화를 조사하였 다. 이러한 저온 소결용 유전체 세라믹스가 MLCC의 응용시 Pt-Pd계의합금을 내부전극으로 사용가능성을 검토하였다. Flux를 4mol%첨가한 TiO3-0.04Ba(Cu,Mo)O3 조성의 유전체는 120$0^{\circ}C$의 온도에서 2시간 소결했을 경우 소결밀도는 이론밀도의 95% 에 근접하였으며 이때 의 비유전율은 8000이상을 나타내었다. 이러한 소결 온도의 감소는 저융점인 ba(Cu,Mo)O3 계의 flux가 첨가되면서 비교적 낮은 온도에서 액상을 형성하여 소결을 촉진시켰기 때문으 로 사료된다.

Synthesis and Characterization of Molybdeum Complexes with Schiff-Bases(II), Dioxobis(N-aryl-3-methoxysalicyaldiminato) Molybdenum(VI) Complexes (몰리브덴의 시프-염기착물의 합성과 그 성질 (제2보). 다이옥소비스(질소-아릴-3-메톡시살리실알디미나토)몰리브데늄(VI) 착물)

  • O, Sang O;Gu, Bon Gwon
    • Journal of the Korean Chemical Society
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    • v.29 no.3
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    • pp.257-264
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    • 1985
  • Dioxobis(3-methoxysalicyaldehydato)molybdeum(VI) complex has been synthesized by reactions of 3-methoxysalicylaldehyde and ammonium paramolybdate in methanol solution. With appropriate primary amine, the resulting complex gave schiff-base complexes, MoO$_2$(CH$_3$O-sal-N-R)$_2$ in which C=O oxide ligands had been replaced by nitrogen. The properties and possible molecular structure of these complexes were discussed by elemental analysis, spectroscopic studies and electric conductivities measurements. It was found that the Mo(VI) complexes contain a cis-MoO$_2$ group since their infrared spectra two Mo=O band at about 900cm$^{-1}$ and the combining ratios for MoO$_2$-ligand are 1 : 2. Also, electronic spectra of molybdenyl complexes assigned to ligand-to-metal charge transfer transition. All of these complexes are yellow or orange, depolar compound and slightly soluble in alcohol, dichloromethane, chloroform and N,N-dimethylformamide.

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Interaction of Oxygen and $CH_4$ with Molybdenum Oxide Catalysts

  • Kim, C. M.
    • Bulletin of the Korean Chemical Society
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    • v.18 no.10
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    • pp.1082-1085
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    • 1997
  • The Near-Edge X-ray Absorption Fine Structure (NEXAFS) technique and Differential Scanning Calorimetry (DSC) were utilized to investigate the reaction of CH4 and O2 on the MoO3/SiO2 catalyst. The NEXAFS results showed that the stoichiometry of the molybdenum oxide catalyst supported on silica was MoO3. MoO3 was reduced to MoO2 when the catalyst was exposed to CH4 at 773 K. NEXAFS results confirm that lattice oxygen is directly related to the process of CH4 oxidation which takes place on the surface of MoO3/SiO2 catalysts. DSC results show that the structure of MoO3 changes around 573 K and this structural change seems to improve the migration of oxygen in the lattice.

Effect of MoS$_2$ and $Fe_2O_3$ Additives on the Tribological Behavior of the Plasma Sprayed Zirconia Based Coatings (MoS$_2$$Fe_2O_3$ 첨가제가 지르코니아계 용사코팅층의 마모마찰 특성에 미치는 영향)

  • 신종한;임대순;안효석
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1997.10a
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    • pp.93-99
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    • 1997
  • High Temperature wear behavior of plasma sprayed ZrO$_2$ and MoS$_2$, $Fe_2O_3$ coatings were investigated for high temperature wear resistance applications. The MoS$_2$, $Fe_2O_3$ added powders containing 2.5, 5.0, 7.5, 10.0 mol% of $MoS_2$, $Fe_2O_3$ for plasma spray were made by spray drying method. Wear test were performed at temperature ranges from room temperature to 600$\circ$C. The microstructural change of coatings and the worn. surface were examined by SEM and XRD. In ZrO$_2$ coating, the coefficient of friction and wear amount of room temperature to 400$\circ$C was increased with temperature and decreased with temperature over 400$\circ$C. The coefficient of friction and wear amount of MoS$_2$ added coatings were increased with temperature, but those of $Fe_2O_3$ added coatings had lower coefficient of friction and higher wear resistance than ZrO$_2$ coating.

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