A simple approach to controllably grow network-like branched single-crystalline Si3N4 nanostructures

We reported a simple, large-scale, and controllable growth method for network-like branched single-crystalline Si3N4 nanostructures by catalyst-assisted pyrolysis of a polysilazane. The templates were a silicon wafer deposited with a 5 nm Fe film. The processes simply involved in thermal cross-linking of the polymer precursor, crushing of the solidified preceramic polymer chunks into fine powder, and thermal pyrolysis of the powder under the protection of ultra-high purity nitrogen. The collected white network-like branched nanostructures were formed through “metal-absorption on the surface of nanostructures” model by vapor-liquid-solid mechanism. Microstructure characterizations indicate that the nanostructures are single-crystalline hexagonal α-Si3N4. The reaction mechanism of Si3N4 nanonetworks was also proposed.

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