Effect of Temperature on the Microstructure of Boron Nitride Formed In Situ on Chemical Vapor-Deposited Boron in Ammonia Gas
Abstract:Boron nitride thin layers are in situ fabricated on chemical vapor-deposited boron in ammonia gas. Characterization by X-ray photoelectron spectroscopy and transmission electron microscopy reveals that the nitridation is dominated by different processes with varying temperatures. Below 1300°C the surface reaction is in control and leads to the formation of uniformly thin layer with mostly sp3 boron nitride. As the temperature rises, the nitridation is gradually turned as a diffusion-determining process, after which a thicker but uneven layer with hexagonal sp2 boron nitride is produced.
Document Type: Research Article
Affiliations: 1: National Key Laboratory of Thermostructure Composite Materials, Northwestern Polytechnical University, Xi'an 710072, China 2: Key Laboratory of High Performance Ceramic Fibers, College of Materials, Xiamen University, Ministry of Education, Xiamen 361005, China
Publication date: March 1, 2011