Sol-Gel-Process in the Ammono-System – a Novel Access to Silicon Based Nitrides
✍ Scribed by Josua Löffelholz; Josef Engering; Martin Jansen
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- German
- Weight
- 150 KB
- Volume
- 626
- Category
- Article
- ISSN
- 0372-7874
No coin nor oath required. For personal study only.
✦ Synopsis
Controlled coammonolysis of elementalkylamides in aprotic organic solvents at low temperatures have been shown to result in the formation of polyazanes. The synthetic procedure developed may be addressed as ªsol-gel-route in the ammono systemº. Pyrolysis of these novel polymer precursors gave access to multinary nitrides. For the model systems Si(NHMe) 4 /B(NMe 2 ) 3 , Si(NHMe) 4 /Ti(NMe 2 ) 4 , and Si(NHMe) 4 /Ta(NMe 2 ) 5 polymeric boro-, titano and tantalosilazanes were obtained. Pyrolysis in ammonia at 1000 °C yielded amorphous silicon boron nitride, silicon titanium nitride and silicon tantalum nitride powders; further heating of the nitride powders at 1500 °C in nitrogen atmosphere led to the formation of partly crystalline composites of a-Si 3 N 4 and amorphous silicon boron nitride for the Si/B/N system, a composite of finely dispersed TiN and amorphous silicon titanium nitride for the Si/Ti/N system, and crystalline TaN and amorphous silicon nitride for the Si/Ta/N system. Furthermore, the structure and pyrolysis chemistry of the polymeric intermediates, as well as the morphology of the pyrolysis products, were studied by NMR, MAS-NMR, FT-IR, DTA-TG-MS, XRD, SEM, EDX and elemental analyses.