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|Section2= |Section3= }} 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 reacting 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, ISBN 0-07-049439-8〕 The room temperature form NbO2 has a tetragonal, rutile-like structure with short Nb-Nb distances indicating Nb-Nb bonding.〔Wells A.F. (1984) ''Structural Inorganic Chemistry'' 5th edition Oxford Science Publications ISBN 0-19-855370-6 〕 High temp 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 to carbon and sulfur dioxide to sulfur.〔 In an industrial process for the production of niobium metal(), NbO2 is produced as an intermediate, by the hydrogen reduction of Nb2O5.〔Patent EP1524252, Sintered bodies based on niobium suboxide, Schnitter C, Wötting G 〕 The NbO2 is subsequently reacted with magnesium vapour to produce niobium metal.〔Method for producing tantallum/niobium metal powders by the reduction of their oxides by gaseous magnesium, US patent 6171363 (2001), Shekhter L.N., Tripp T.B., Lanin L.L. (H. C. Starck, Inc.)〕 ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Niobium dioxide」の詳細全文を読む スポンサード リンク
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