X-ray absorption near edge structure study of BN nanotubes and nanothorns |
| |
Authors: | Choi Hyun Chul Bae Seung Yong Jang Woo Sung Park Jeunghee Song Ha Jin Shin Hyun-Joon |
| |
Institution: | Department of Chemistry, Korea University, Jochiwon 339-700, Korea. |
| |
Abstract: | Two boron nitride (BN) nanostructures, the bamboo-like nanotubes and nanothorns where the nanosize h-BN layers are randomly stacked looking like thorns, were synthesized selectively via thermal chemical vapor deposition of B/B(2)O(3) under the NH(3) flow at 1200 degrees C. Electron energy-loss spectroscopy reveals the N-rich h-BN layers with a ratio of B/N = 0.75-0.85. Angle-resolved X-ray absorption near edge structure of these two N-rich nanostructures has been compared with that of h-BN microcrystals. The pi transition in the N K-edge shifts to the lower energy by 0.8-1.0 eV from that of h-BN microcrystals, and the second-order signals of N 1s electrons become significant. We suggest that the N enrichment would decrease the band gap of nanostructures from that of h-BN microcrystals. The Raman spectrum shows the peak broadening due to the defects of N-rich h-BN layers. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|