Effect of surrounding gas temperature on the morphological evolution of TiO2 nanoparticles generated by laser ablation in tubular furnace
- 205 Downloads
Titanium oxide nanoparticles are synthesized by laser ablation of Ti target in oxygen atmosphere under well-controlled temperature profiles in a tubular furnace. The size and the shape of generated nanoparticles are varied by changing the temperature of furnace. The mobility-based size distributions of generated air-borne nanoparticles are measured using a scanning mobility particle sizer, and the size distributions of primary particles are analyzed by a scanning electron microscope. When the particles are generated by laser ablation at the room temperature, the particles are agglomerates in gas phase with the average mobility diameter of 117 nm and the mean diameter of primary particles of 11 nm. The primary particle diameter increases from 11 to 24 nm by raising the furnace temperature up to 800 °C. Since the mass of Ti vapor ablated from a target is found to be constant regardless of the furnace temperature, this particle growth may be attributed to the reduction in nuclei number as a result of mild quenching at higher temperatures. As the temperature reaches higher than 1,000 °C, the mobility diameter suddenly drops and the primary particle diameter increases due to sintering, and at 1,200 °C the mobility diameter coincides with the primary particle diameter. Since the laser oven method offers an independent control of vapor concentration and the temperature of surrounding atmosphere, it is an effective tool to study the formation process of nanoparticles from primary particles with a given size.
KeywordsTitania nanoparticles Aerosol Laser ablation Agglomeration Nucleation Sintering
The authors thank Dr. Kenji Koga at National Institute of Advanced Industrial Science and Technology for his help in carrying out the measurement by transmission electron microscope. This study was supported by a Grant-in-Aid for Scientific Research on Scientific Research (b) (No. 23360338) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.
- Jang HD, Friedlander SK (1998) Restructuring of chain aggregates of titania nanoparticles in the gas phase. Aerosol Sci Technol 29:81–91Google Scholar
- Lide DR (2003–2004) CRC handbook of chemistry and physics, 84th edn. CRC Press, Boca Raton, pp 6–73Google Scholar
- Matsui I (2006) Preparation of FePt magnetic nanoparticle film by plasma chemical vapor deposition for ultrahigh density data storage media. Jpn J Appl Phys 45:10BGoogle Scholar