Tungsten oxynitride

Kartachova, O., A. M. Glushenkov, Y. Chen, H. Zhang, X. J. Dai, and Y. Chen. 2012. Electrochemical capacitance of mesoporous tungsten oxynitride in aqueous electrolytes. Journal of Power Sources 220 298-305. 

Tungsten oxynitride nanowires with a high surface area of 221 m /g were prepared via a nitridation process of tungsten oxide nanowires (47). In the flrst... 

The possibility of the incorporation of oxygen into the particle is particularly relevant for the carbides and nitrides of molybdenum and tungsten which possess a high affinity for this element.13,23 The oxygen may come from the carbonyl precursor, and result in oxycarbide or oxynitride formation in the core of the nanoparticle itself.16 Exposure to the ambient can also result in the formation of surface oxycarbides and oxynitrides with catalytic properties different from those of the pure nitride or carbide phase.15,24-26 However, heat treatment of these nanoparticles with a mixture of methane/hydrogen or ammonia/hydrogen should convert the surface to a pure nitride or carbide form. 

In this process, the substrate is placed inside a reactor supplied by different gases [21], The principle of the process is that a chemical reaction takes place between the source gases producing a solid material which condenses on all surfaces inside the reactor. CVD is widely used in the semiconductor industry to deposit various materials such as polycrystalline, amorphous, and epitaxial silicon, carbon fiber, filaments, carbon nanotubes, Si02, silicon-germanium, tungsten, silicon nitride, silicon oxynitride, titanium nitride, and various high-k dielectrics. 

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