Oxynitride solution

This model goes a long way towards explaining most experimental results reported in the literature for ISFETs with oxide or nitride surfaces. Unfortunately, the properties of these materials prepared in different laboratories are very different. It is known that silicon nitride (really silicon oxynitride SisNztOx) forms an oxygen-rich layer at the surface, whose thickness depends on the deposition conditions. This passivation layer forms rapidly (in a matter of hours) and is very stable, even under continuous exposure to aqueous electrolyte. The hydration of this layer seems to fit the requirements and predicted behavior of the Sandifer model. Consequently, ISFETs that have been exposed to aqueous solution for more than one hour show no adsorption effects which would be expected from the SBT model. 

Mixed oxide, Al203-Si02, bond phases are generally the next most corrosion resistant to acids including low quantities of HF. Silicon nitride and silicon oxynitride bonded silicon carbides perform similarly to mixed oxide bonds. Table 19-2 shows typical weight loss and retained strength values for these products in contact with common acidic solutions for the times and temperatures shown. ... 

Neutron diffraction data on a pure sample of Sr2 01(, N found the interlayer gap void of hydrogen [148]. Further its reaction with D, leads smoothly to a mixture of SrND and SrD2 [149, 150] and not to Sr2NDx as suggested previously. Since SrN , SrNH. and SrOxNv arc all black materials with the rocksalt structure (a = 5.495, 5.46, and 5.473 A, respectively), it is likely that SrN is actually the imide or an oxynitride solid solution. We believe that the expected composition Sr3N2 has yet to be observed as a pure phase. 

Preparation of Alkali-Earth Tantalum Oxynitride Photocatalyst Worked under Visible Light Utilized by Ammonia Solution of an Alkali-earth Metal... 

Sato [1939SAT] has measmed the mean heat capacity of a sample whose composition was essentially equivalent to a mixture of Th3N4(cr) and Th02(cr) over three temperature ranges from 273.2 to 776.2 K. However as noted in Appendix A, it is not clear whether this was simply a mixture or a solid solution of these phases (and thus close to the composition of the oxynitride Th2N20(cr)), and these data have not been considered further in the review. 

Pt-based catalysts are two necessary approaches at the current technology stage. It is believed that non-noble metal electrocatalysts is probably the sustainable solution for PEM fuel cell commercialization. In the past several decades, various nonnoble metal catalysts for ORR have been explored, including non-pyrolyzed and pyrolyzed transition metal nitrogen-containing complexes, transition metal chalcogenides, conductive polymer-based catalysts, metal oxides/carbides/nitrides/ oxynitrides/carbonitrides, and enzymatic compoimds. The major effort in non-noble metal electrocatalysts for ORR is to increase both the catalytic activity and stability. 

The a P transformation in silicon nitride requires a lattice reconstruction. This type of process occurs usually only when the transforming material is in contact with a solvent. The greater solubility of the more unstable a form drives it into solution after which it precipitates as the less soluble, more stable P form. The predominantly a silicon nitride powder used to produce dense silicon nitride ceramics is observed to transform to the P modification during the sintering process at temperatures in excess of 140QOC when the original a phase is in contact with a M-Si-O-N (M = Mg, Y, etc) oxynitride liquid phase. 

Silicon nitride powder particles are contaminated by layers of silica on their surfaces. Oxide additives MxOy mixed with silicon nitride react with this silica and some of the nitride itself at sintering temperatures to form an oxynitride liquid which promotes liquid phase sintering and densification by solution-precipitation [1, 6, 10]. The a-Si3N4 dissolves in the liquid and is... 

Metallic nitrides can be alloyed with other nitrides and carbides of transition metals to give solid solutions, as shown in Table 3 (4). Complete solid solubility has been demonstrated for a great number of combinations. Continuous alloys seem to be formed when the crystal structure and bonding in the materials are similar and when the parent metals by themselves form solid solutions with each other. For example, all cubic monocarbides and mononitrides of group 4 and 5 metals show complete miscibility with the exception of the pairs ZrN-VN, HfN-VN, ZrN-VC, HfN-VC, and HfC-VN (11). Recent developments in ternary and quaternary nitride chemistry have also been reviewed (16). Similarly, materials of mixed C, N, and O compositions are common, and oxycarbides, oxynitrides, and oxycarbonitrides have been reported (17). Oxygen is particularly ubiquitous, and even materials that are normally pure may contain substantial amounts of dissolved oxygen. 

The aluminophosphate oxynitride containing 13.7% nitrogen has been used as support for the preparation of the nickel supported AlPON. Pore volume impregnation with an aqueous solution of nickel formate was used. After impregnation, the solid was dried at 170 °C under a residual pressure of approximately 5 mbar for 12 h. 

The principle of the chemical analysis of nitrogen is based on the reaction of the nitride ions N - with a strong base and the formation of anunonia which is then titrated, hi the case of refractmy oxynitrides, the difficulties of the alkaline attack in solution has been solved by using another procedure (30). The oxynitrides are reacted at 400 with melted potassium hydroxide under inert atmosphere. 

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