Fabrication of Fe-Al nanoparticles by selective oxidation of Fe-Al thin films
1 Department of Optical Engineering, Cheongju University, Cheongju, 360-764, South Korea
2 Department of Semiconductor Engineering, Cheongju University, Cheongju, 360-764, South Korea
3 Department of Applied Chemistry, Cheongju University, Cheongju, 360-764, South Korea
Nanoscale Research Letters 2013, 8:152 doi:10.1186/1556-276X-8-152Published: 2 April 2013
The possibility of a new technique for fabricating nanoparticles from thin films using selective oxidation in an atmosphere mixture of water vapor and hydrogen was investigated. Fe-5wt.%Al films were RF-sputtered and annealed in the atmosphere mixture at 900°C for up to 200 min, in order to oxidize aluminum selectively. Thermodynamics simulation showed that temperatures exceeding 800°C are necessary to prevent iron from being oxidized, as confirmed by the depth profile of XPS. As the annealing time increased, the morphology of the 200-nm Fe-Al films changed from the continuous to the discontinuous type; thus, particulate Fe-Al films formed after 100 min. The particulate 10- to 100-nm Fe-Al films showed super-paramagnetic behavior after the oxidation. Thus, a new technique for fabricating nanoparticles was successfully introduced using selective oxidation.