Oxynitride feature

The last three chapters summarize unique structural and chemical features of a variety of glasses. They also provide an overview of the important aspects of the glass systems. Chapters 12 and 13 discuss respectively oxide and chalcogenide glasses particularly in view of their chemistry, structure and a number of special phenomena associated with them. In chapter 14, synthesis, structure and properties of halide, oxyhalide, oxynitride and metallic glasses are discussed. Some aspects of glass-like carbon have also been presented. 

One common feature of all oxynitride glasses is that th are black. This blackness is not an intrinsic phenomenon of the materials themselves, but rather is consistent with the similar dark color of silicon nitride materials, especially those which have been produced at higher temperatures, and also in a carbon-rich environment It is now known that the dark color is due to a fine dispersion of metaDic particles within the glass [51], which form fundamentally as a result of trace metaDic impurities... 

IR data (vSiN 820-833 cm ) were used to characterise SiN films formed by a variety of CVD techniques. The IR spectra of amorphous SiOxN3 thin films included vSiO and vSiN features at 1105 cm", 865 cm respectively Two other reports have been made of IR spectra of CVD-produced silicon nitride and oxynitride films " " The FTIR spectrum of an SisN4 powder shows a feature at 1200 cm corresponding to the presence of Si-O units ... 

The colors of these perovskites span over a rather wide range, being originated by different mechanisms. Bandgap colors feature the oxynitride perovskites, while metal-oxygen charge transfer, often associated with intervalence charge transfer and crystal field electronic transitions, characterizes the oxidic phases. 

In nitride synthesis, the ammonia reduces the oxidic precursor to sub-oxides or oxynitrides before final nitridation. The process is manifested by features appearing on the MS traces of H2, N2, and H2O. No features are observed for the NH3 signal, tracked as mass 15, due to the high signal level of the parent mass 17. 

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