Crystalline and amorphous thin films of tungsten(VI) oxide can be prepared by chemical vapor deposition using a variety of volatile precursors below 500 Β°C. Deposition parameters for preparation of WO 3 films from tungsten hexacarbonyl [W(CO) 6 ], tungsten hexafluoride (WF 6 ), tungsten ethoxides [W
Vapor phase deposition of polybenzoxazoles
β Scribed by Lon J. Mathias; Tina L. Grubb; Gordon L. Tullos
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 388 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0887-624X
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β¦ Synopsis
Vapor phase deposition was carried out on multifunctional aliphatic and aromatic benzoxazoles to yield powdered samples of poly(dimethylenebenzoxazoles). Representative aliphatic and aromatic poly(dimethylenebenzoxazoles) were also synthesized through solution methods using 4-amino-3-hydroxyhydrocinnamic acid and 2-(4-(bromomethyl)phenyl)-6-(bromomethyl)benzoxazole, respectively, as monomers. Both aromatic and aliphatic polybenzoxazoles containing {CH 2 CH 2 { units in the polymer backbone displayed catastrophic weight loss over a very narrow temperature range. This is in contrast with other polybenzoxazoles which show a gradual weight loss over 500-1000ΠC. Vapor phase deposition carried out under vacuum on the polymers gave similar polymers in the collection zone suggesting the catastrophic weight loss is attributed to thermal depolymerization of the polymer through a diradical intermediate similar to the thermolysis and polymerization of [2.2]paracyclophane.
π SIMILAR VOLUMES
GaN layers were grown on c-plane sapphire by metalorganic vapor phase epitaxy (MOVPE) using a hot tungsten filament for the ammonia (NH 3 ) precracking. A two flows horizontal growth chamber was specially designed to eliminate parasitic reactions between TMG and NH 3 and avoid TMG decomposition on t