3236-82-6Relevant academic research and scientific papers
Electrochemical synthesis of niobium(V) ethylate
Berezkin,Chernykh,Polyakov,Tomilov
, p. 741 - 745 (2006)
The effect exerted by the supporting electrolyte and cathode material on the anodic dissolution of niobium in ethanol solutions was studied. Pleiades Publishing, Inc., 2006.
Synthesis and the luminescent properties of CdNb2O6 oxides by sol-gel process
Hsiao, Yu-Jen,Chang, Yee-Shin,Chen, Guo-Ju,Chang, Yen-Hwei
, p. 259 - 262 (2009)
Synthesis and luminescence properties of CdNb2O6 oxides by the sol-gel process were investigated. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence spectroscopy and absorption spectra. The PL spectra excited at 272 nm have a broad and strong blue emission band maximum at 460 nm, corresponding to the self-activated luminescence center of CdNb2O6. The optical absorption spectra of the 700 °C sample exhibited the band-gap energies of 3.35 eV. Furthermore, the microstructure and luminescence spectra of the products were investigated.
Synthesis of potassium niobate from metal alkoxides
Amini,Sacks
, p. 53 - 59 (1991)
Preparation of potassium niobate from metal alkoxides was investigated. Potassium-niobium ethoxide, KNb(OC2H5)6, and potassium-niobium propoxide, KNb(OC3H7)6, were synthesized and subsequently hydrolyzed using several water concentrations (0.75 to 6.0 mol of water/(mol of alkoxide)). Rapid precipitation of potassium-deficient particles occurred when higher concentrations of water were used. This resulted in the formation of a multiphase material after calcination, as X-ray diffraction showed the presence of both KNbO3 and potassium-deficient oxide phases(s). Single-phase KNbO3 could be prepared by two methods: (1) hydrolysis of KNb(OC3H7)6/propanol solutions using 1 mol of water (per mole of propoxide) added as a water/propanol solution and (2) hydrolysis of KNb(OC2H5)6/ethanol solutions using 1 mol of water (per mole of ethoxide) added as a water/methanol solution. The latter method provided advantages of low calcination temperature for the formation of single-phase KNbO3 and low weight loss after calcination.
Polymorphism in micro-, Submicro-, and nanocrystalline NaNbO3
Shiratori, Yosuke,Magrez, Arnaud,Dornseiffer, Juì?rgen,Haegel, Franz-Hubert,Pithan, Christian,Waser, Rainer
, p. 20122 - 20130 (2005)
NaNbO3 powders with various particle sizes (ranging from 30 nm to several microns) and well-controlled stoichiometry were obtained through microemulsion-mediated synthesis. The effect of particle size on the phase transformation of the prepared NaNbO3 powders was studied using X-ray powder diffraction, Raman spectroscopy, and nuclear site group analysis based on these spectroscopic data. Coarsened particles exhibit an orthorhombic Pbcm (D2h11, no. 57) structure corresponding to the bulk structure, as observed for single crystals or powders prepared by conventional solid-state reaction. The crystal symmetry of submicron powders was refined with the space group Pmc21 (C2v2, no. 26). The reduced perovskite cell volumes of these submicron powders were most expanded compared to all the other structures. Fine particles with a diameter of less than 70 nm as measured from SEM observations showed an orthorhombic Pmma (D 2h5, no. 51) crystal symmetry. The perovskite formula cell of this structure was pseudocubic and was the most compact one. A possible mechanism of the phase transformation is suggested. ? 2005 American Chemical Society.
Sol-gel synthesis and the luminescent properties of CaNb2O6 phosphor powders
Hsiao, Yu-Jen,Liu, Chien-Wei,Dai, Bau-Tong,Chang, Yen-Hwei
, p. 698 - 701 (2009)
Synthesis and luminescence properties of CaNb2O6 oxides by the sol-gel process were investigated. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence spectroscopy and absorption spectra. The PL spectra excited at 257 nm have a broad and strong blue emission band maximum at 457 nm, corresponding to the self-activated luminescence of the niobate octahedra group [NbO6]7-. The optical absorption spectra of the 700 °C sample exhibited the band-gap energies of 3.53 eV.
Synthetic method of niobium alkoxide
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Paragraph 0032-0033, (2020/06/29)
The invention discloses a novel synthesis method of niobium alkoxide. The method includes: 1) preparing the following raw materials: anhydrous alcohol, an alkane mixture, metal sodium and a niobium pentachloride.tetrahydrofuran suspension; 2) carrying out reaction on anhydrous alcohol, the alkane CnH2n+2 mixture and metal sodium reaction under certain condition; 3) adding the niobium pentachloride.tetrahydrofuran suspension for reaction; and 4) pressure reduced rectification and pressure reduced distillation so as to obtain the product niobium alkoxide. The synthesis method provided by the invention solves the disadvantages of long process, poor environment, high cost, low recovery rate and the like in existing synthesis process of niobium alkoxide by ammonia technique, and has the advantages of smooth reaction and distillation conditions, easy control, no production of toxic and harmful gas during synthesis, cheap raw materials, and high reaction yield and production efficiency, etc. Also, the synthesis reaction has a total yield up to 89%, and the raw material alkane is non-toxic, can be reused and does not generate any waste. Therefore, the method not only is suitable for laboratory synthesis, but also is suitable for large-scale synthesis.
PROCESSES FOR PREPARING NIOBIUM ALKOXIDES, AND NIOBIUM ALKOXIDES PREPARED THEREBY
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Page/Page column 4, (2008/06/13)
Processes for preparing high-purity niobium alkoxides, especially niobium ethoxide, are described which include: (a) providing a crude niobium alkoxide starting material comprising at least one compound of the general formula (I) [in-line-formulae]Nb(OR)5 ??(I)[/in-line-formulae]wherein each R independently represents a linear or branched C1-12 alkyl group; and (b) contacting the crude niobium alkoxide starting material with a treatment medium comprising a component selected from the group consisting of (i) one or more alcohols of the general formula (II) in an amount of 0.01 to 5% by weight, (ii) air or an oxygen-containing gas, and (iii) combinations thereof; [in-line-formulae]R1OH ??(II)[/in-line-formulae]wherein each R1 independently represents a linear or branched C1-12 alkyl group.
Process for the preparation of high-purity zirconium, hafnium, tantalum and niobium alkoxides
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, (2008/06/13)
A novel process for the preparation of high-purity zirconium, hafnium, tantalum and niobium alkoxides (alcoholates), novel tantalum and niobium compounds and a process for their preparation are provided. The process comprises the steps of mixing crude metal alkoxides M(OR)x having a halogen impurity of at least 0.05 wt. %, with an alcohol ROH, in which R is a C1-C12-alkyl radical, and subsequently or simultaneously metering in an excess of ammonia, based on the amount of mononuclear or polynuclear halogen-containing metal alkoxides.
Metal organic precursors for transparent metal oxide thin films and method of making same
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, (2008/06/13)
A liquid precursor for forming a transparent metal oxide thin film comprises a first organic precursor compound. In one embodiment, the liquid precursor is for making a conductive thin film. In this embodiment, the liquid precursor contains a first metal from the group including tin, antimony, and indium dissolved in an organic solvent. The liquid precursor preferably comprises a second organic precursor compound containing a second metal from the same group. Also, the liquid precursor preferably comprises an organic dopant precursor compound containing a metal selected from the group including niobium, tantalum, bismuth, cerium, yttrium, titanium, zirconium, hafnium, silicon, aluminum, zinc and magnesium. Liquid precursors containing a plurality of metals have a longer shelf life. The addition of an organic dopant precursor compound containing a metal, such as niobium, tantalum or bismuth, to the liquid precursor enhances control of the conductivity of the resulting transparent conductor. In a second embodiment, a liquid precursor for forming a transparent metal oxide nonconductive thin film comprises an organic precursor compound containing a metal from the group including cerium, yttrium, titanium, zirconium, hafnium, silicon, aluminum, niobium, tantalum, and bismuth. Liquid precursors of the invention preferably comprise a metal organic precursor compound, such as an ethylhexanoate, an octanoate, or a neodecanoate, dissolved in a solvent, such as xylenes, n-octane and n-butyl acetate.
Niobium-93 Nuclear Magnetic Resonance Studies of the Solvolysis of NbCl5 by Alcohols
Lee, G. Robert,Crayston, Joe A.
, p. 3073 - 3076 (2007/10/02)
Niobium-93 and 1H-NMR spectroscopy have been used to identify the substitution products NbCl5-x(OMe)x formed by the stepwise substitution of NbCl5 by MeOH in non-co-ordinating solvents.This reveals evidence for all of the possible su
