Nanosized aluminum nitride powder

The sur ce FT-IR stey of a nanosize aluminum nitride powder definitely brought evidence of the specific chemical composition of its first atomic layer. The unavoidable contamination, mainly by atmospheric water, implies the presence of oxygen and hydrogen in this first layer. As a result, a comparison with the alumina sur ce appeared quite reasonable. Indeed, methanol and pyridine used as probe molecules showed the same behavior on both material sur ces. The acidity of the AIN sur ce was proven by the presence of two types of Al Lewis sites. However for AIN, a specific dissociative adsorption mechanism of acidic methanol could be possibly explained by the presence of weakly basic AI3N sites. Besides, the isotopic exchange... 

Therefore, we can synthesize aluminum nitride powders in a wide range of sizes - from nanosized to micron powders with various morphologies (spherical, laminar, thread- and needle-like) by changing aluminum combustion temperature, nitrogen pressure, and the initial mixture composition. Each size can be considered as optimum for specific appUcations. 

The surfaces of oxide nanopowders have been extensively studied either for characterization purposes or for potential catafytic properties investigatioa As for non-oxide ceramic powders, references on their surface studies are scarce. Due to hydrolysis in ambient atmosphere, the unavoidable presence of oxygen in the first atomic layer of these nanostructured powders may drastically modify their expected properties. After briefly introducing our characterization technique of nanosized powder sur ces, we will present as an exan le, the Fourier transform infixed (FT-IR) sur ce analysis of a nanostructured aluminum nitride powder obtained via sol-gel type chemical synthesis. 

Structural and Morphological Peculiarities of Silicon, Boron, and Aluminum Nitrides - Nanosized Powders... 

I 9 AIN Ceramics from Nanosized Plasma Processed Powder, its Properties and Application Table 9.1 Characteristics of aluminum nitride ceramics. 

The plasma technique allows also production of nanosized nitride powder doped with sintering additives, for example, aluminum nitride doped with yttria. Such composite powders are characterized with high degree of homogeneity because the formation of powder particles occurs by simultaneous condensation from gaseous-vapor phase [13]. 

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