1 monoxide Titanium

Titanium Monoxide. Titanium monoxide [12137-20-17, TiO, has a rock-salt stmcture but can exist with both oxygen and titanium vacancies. For stoichiometric TiO, the lattice parameter is 417 pm, but varies from ca 418 pm at 46 atom % to 4I62 pm at 54 atom % oxygen. Apparendy, stoichiometric TiO has ca 15% of the Ti and O sites vacant. At high temperatures (>900° C), these vacancies are randomly distributed at low temperatures, they become ordered. Titanium monoxide may be made by heating a stoichiometric mixture of titanium metal and titanium dioxide powders at 1600°C... 

Alternative methods of production include reduction of HO2 with magnesium, which yields TiO only. When titanium monoxide is heated in air at 150—200°C, titanium sesquioxide, Ti202, forms, and at 250—350°C, it changes to Ti O. ... 

The vapor pressure of titanium monoxide is much higher than that of zirconium monoxide and hafnium monoxide. However, sacrificial deoxidation is not feasible for titanium because of the relatively high vapor pressure of titanium metal itself. The limiting R value for the titanium-oxygen system is equal to 0.1. 

Titanium malates, 25 89 Titanium metal, 25 61 Titanium methoxides, 25 78 Titanium mill shipments, 24 839 Titanium monosulfide, 25 57 Titanium monoxide, 25 13-14 Titanium monoxychloride, 25 53 Titanium nitrate, 25 10-11 Titanium nitride(s), 25 9-10... 

An interesting group of non-stoichiometric oxides are the transition-metal monoxides (MO, where M = metal) for example, titanium monoxide (TiO) and vanadium monoxide (VO). These have a wide range of non-stoichiometric... 

T. J. Groshens, 1. Molecular Vapor Synthesis The Use of Titanium Monoxide and Vanadium Monoxide. 2. Oxidative Insertion Reactions of First Row Early Transition Metal Atoms, Ph. D. Thesis, Kansas State University, 1988. 

Many of the oxides, carbides, and nitrides with the NaCl structure tend to be nonstoichiometric. Titanium monoxide exists over the range Tio.ssO to TiO, while FeO never occurs it is always nonstoichiometric with a composition ranging from Feo.goO to Feo.geO. As a consequence of these vacancies, the transition metal exists in two valence states, causing the oxide to exhibit semiconductor properties (as for NiO). 

Apart from the well-known titanium-dioxide phases mentioned above, other titanium oxides exists such as titanium hemioxide (Ti O), titanium monoxide (TiO), titanium ses-quioxide (Ti O,), and anosovite (TijOj). 

Titanium monoxide or hongquiite [12137-20-1], chemical formula TiO, exhibits a very wide range of composition, extending approximately from 42 to 54 at. % oxygen (TiO to TiOj j ). It may be prepared by direct reduction by mixing stoichiometric amounts of titanium metal and titanium dioxide into a molybdenum crucible at 1600°C or reduction of the titanium dioxide with hydrogen under pressure at 130 atm and 2000°C. 

D. Watanabe, O. Terasaki, A. Jostsons, and J. R. Castles, Electron microscope study on the structure of low-temperature modification of titanium monoxide phase, in The Chemistry of Extended Defects in Non-Metallic Solids (L. Eyring and M. O Keeffe, eds.), pp. 238-256, North-Holland, Amsterdam (1970). 

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