科研之友
微信
新浪微博
Facebook
分享链接
摘要
Monodisperse Fe100-x Pt (x) (x=37, 41, 47, 54, 61, 66, 74) nanoparticles with an average size of 4.5 nm were successfully synthesized using the chemical polyol process. As-synthesized Fe100-x Pt (x) nanoparticles have the chemically disordered face-centered cubic (fcc) structure with A1 phase. To achieve an ordered structure L1(0) phase for FePt and L1(2) phase for FePt3 particles, high-temperature annealing is required. In this work, with optimizing effective parameters of annealing and also by changing the stoichiometric of Fe100-x Pt (x) nanoparticles, we were able to achieve coercivity of 16,500 Oe for Fe53Pt47, which is heat treated at 650 C-a similar to for 60 min with 20 C-a similar to/min (annealing heating rate). It is obvious that the annealing procedure in this temperature leads to destruction of surfactant and sintering. In this work, chemically synthesized Fe53Pt47 nanoparticles were coated by a nonmagnetic CoO oxide shell to prevent them from sintering. Results show that the size of the core/shell (Fe53Pt47/CoO) nanoparticles after the annealing at a temperature of 650 C-a similar to has not changed compared to the size of the as-synthesized state. Meanwhile, the coercivity of about 5580 Oe is obtained for this nanocomposite.
- 出版日期2013-12
