A novel technique to extract Bi from mechanochemically prepared Bi–Fe3O4 nanocomposite

✍ Scribed by M. Mozaffari; J. Amighian; A. Hasanpour

• Book ID: 104079438
• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 176 KB
• Volume: 371
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/j.physb.2005.10.095

✦ Synopsis

The solid-state reduction of Bi 2 O 3 to bismuth (Bi) nanoparticles by high-energy ball milling of raw materials (Bi 2 O 3 and Fe) in air and argon atmospheres has been described. XRD results show that in addition to bismuth, a second phase of nanocrystalline magnetite is also formed. This is due to the formation of Fe 2 O 3 and the subsequent change to Fe 3 O 4 in the course of ball milling. Mean particle sizes of the obtained Bi and Fe 3 O 4 particles were 22 and 18 nm, respectively, using Scherrer's formula. A saturation magnetization of 80 emu/g is achieved for magnetic phase (Fe 3 O 4 ). As both Bi and magnetite were nanosized particles, it was not possible to separate these two phases by the magnetic separation technique. A novel technique based on different thermal expansions of the Bi and Fe 3 O 4 was then used to extract metallic Bi from the as-milled powders.