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Niobium Oxide
Niobium oxide, sometimes called columbium oxide, may refer to: * Niobium monoxide (niobium(II) oxide), NbO * Niobium dioxide (niobium(IV) oxide), NbO2 * Niobium pentoxide Niobium pentoxide is the inorganic compound with the formula Nb2 O5. A colorless, insoluble, and fairly unreactive solid, it is the most widespread precursor for other compounds and materials containing niobium. It is predominantly used in alloyi ... (niobium(V) oxide), Nb2O5 In addition to the above, other distinct oxides exist *general formula Nb3n+1O8n−2 where n ranges from 5 - 8 inclusive, e.g. Nb8O19 (Nb16O38). * Nb12O29 and Nb47O116 Natural niobium oxide is sometimes known as ''niobia''. References {{Chemistry index ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niobium Monoxide
Niobium monoxide is the inorganic compound with the formula Nb O. It is a grey solid with metallic conductivity. Structure and electronic properties NbO adopts an unusual cubic structure, similar to the rock salt structure but with some missing atoms compared to it, so that both niobium and oxygen atoms have square planar coordination geometries. The niobium centers are arranged in octahedra, and there is a structural similarity to the octahedral niobium clusters in lower halides of niobium. In NbO the Nb-Nb bond length is 298 pm which compares to 285 pm in the metal. One study of the bonding concludes that strong and nearly covalent bonds exist between the metal centers. It is a superconductor with a transition temperature of 1.38 K. It is used in capacitors where a layer of Nb2O5 is formed around NbO grains as the dielectric. Preparation NbO can be prepared by reduction of Nb2O5 by H2. More typically, it is prepared by comproportionation: :Nb2O5 + 3 Nb → 5 NbO Referen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niobium Dioxide
Niobium dioxide, is the chemical compound with the formula NbO2. It is a bluish-black non-stoichiometric solid with a composition range of NbO1.94-NbO2.09. It can be prepared by reducing Nb2O5 with H2 at 800–1350 °C. An alternative method is reaction of Nb2O5 with Nb powder at 1100 °C.Pradyot Patnaik (2002), ''Handbook of Inorganic Chemicals'',McGraw-Hill Professional, Properties The room temperature form of NbO2 has a tetragonal, rutile-like structure with short Nb-Nb distances, indicating Nb-Nb bonding. The high temperature form also has a rutile-like structure with short Nb-Nb distances. Two high-pressure phases have been reported one with a rutile-like structure, again with short Nb-Nb distances, and a higher pressure with baddeleyite-related structure. NbO2 is insoluble in water and is a powerful reducing agent, reducing carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom coval ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |