中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 16 No. 1 February 2006 |
（1. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
2. Department of Chemistry and Chemical Engineering, Hunan Building Materials College, Hengyang 421008, China;
3. School of Materials Science and Engineering, Central South University, Changsha 410083, China
Received 19 September 2005; accepted 14 October 2005）
Abstract: A stable δ- and β-bismuth trioxide was prepared at room temperature by vacuum vapor-phase oxidation. The average crystal size of products was 14.6 nm (by XRD), the d(0.5) value was in the range from 62 nm to 69 nm, and geometric standard deviation(GSD) was from 1.42 to 1.64. The results show that δ-Bi2O3 is formed when quenching rates is rapid and β-Bi2O3 is formed when it is slow. The size of grains increases with rising reaction temperature, flow rate of carrier gas, residual pressure of system and longer growing time of grains.
Key words: δ- bismuth trioxide; β-bismuth trioxide; vacuum vapor-phase oxidation; nanometer particles
