Templated non-oxide sol-gel preparation of well-ordered macroporous (inverse opal) Ta3N5 films.
Reactions of Ta(NMe2)5 and n-propylamine are shown to be an effective system for sol-gel processing of Ta3N5. Ordered macroporous films of Ta3N5 on silica substrates have been prepared by infiltration of such a sol into close-packed sacrificial templates of cross-linked 500 nm polystyrene spheres followed by pyrolysis under ammonia to remove the template and crystallize the Ta3N5. Templates with long-range order were produced by controlled humidity evaporation. Pyrolysis of a sol-infiltrated template at 600 °C removes the polystyrene but does not crystallize Ta3N5, and X-ray diffraction shows nanocrystalline TaN plus amorphous material. Heating at 700 °C crystallizes Ta3N5 while retaining a high degree of pore ordering, whereas at 800 °C porous films with a complete loss of order are obtained.
Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom.
Christopher F
CF
Mallinson
Benjamin M
BM
Gray
Andrew L
AL
Hector
Martyn A
MA
McLachlan
John R
JR
Owen
D003460:Crystallization; D017672:Nitrogen Compounds / Q000737:chemistry*; D044367:Phase Transition; D011137:Polystyrenes / Q000737:chemistry; D016062:Porosity; D011437:Propylamines / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013635:Tantalum / Q000737:chemistry*
D017672:Nitrogen Compounds; D011137:Polystyrenes; D011437:Propylamines; D013635:Tantalum; D012822:Silicon Dioxide