Templated Non-Oxide Sol-Gel Preparation of Well-Ordered Macroporous (inverse opal) Ta(3)N(5) Films

[Image: see text] Reactions of Ta(NMe(2))(5) and n-propylamine are shown to be an effective system for sol-gel processing of Ta(3)N(5). Ordered macroporous films of Ta(3)N(5) 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 Ta(3)N(5). 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 Ta(3)N(5), and X-ray diffraction shows nanocrystalline TaN plus amorphous material. Heating at 700 °C crystallizes Ta(3)N(5) while retaining a high degree of pore ordering, whereas at 800 °C porous films with a complete loss of order are obtained.