Microstructural Control of the TiO_2-SnO_2 Binary System and Synthesis of SnO_2 Nanowhiskers by Microwave Irradiation
SnO<SUB>2</SUB> single crystals (columnar crystals and silver grass-like nanowhiskers) were synthesized by selective microwave heating of a TiO<SUB>2</SUB>-SnO<SUB>2</SUB> mixture. The shape of the as-grown SnO<SUB>2</SUB> crystals is strongly dependent on the atmosphere during microwave irradiation. This is due to the difference in growth mechanisms, as revealed by in-situ surface observation under microwave irradiation, in addition to scanning and transmission electron microscopy observations of irradiated specimens. In a N<SUB>2</SUB> atmosphere, silver grass-like SnO<SUB>2</SUB> nanowhiskers were obtained. On the other hand, columnar SnO<SUB>2</SUB> crystals were obtained in air or an O<SUB>2</SUB> atmosphere. Photoluminescence and absorption spectra of the as-grown SnO<SUB>2</SUB> crystals were examined. Based on the analysis of a TiO<SUB>2</SUB>-SnO<SUB>2</SUB> pellet, it was found that the bottom was selectively heated, and SnO<SUB>2</SUB> sublimated by microwave irradiation. A density gradient texture of the sample pellet was formed.
- Materials transactions
Materials transactions 49(4), 879-884, 2008-04-01
The Japan Institute of Metals and Materials