SpringerOpen Newsletter

Receive periodic news and updates relating to SpringerOpen.

Open Access Nano Express

Magnetic Properties of FePt Nanoparticles Prepared by a Micellar Method

Y Gao, XW Zhang*, ZG Yin, S Qu, JB You and NF Chen

Author affiliations

Key Lab of Semiconductor Materials Science, Institute of Semiconductors, CAS, Beijing, 100083, People’s Republic of China

For all author emails, please log on.

Citation and License

Nanoscale Research Letters 2009, 5:1-6  doi:10.1007/s11671-009-9433-4

Published: 16 September 2009


FePt nanoparticles with average size of 9 nm were synthesized using a diblock polymer micellar method combined with plasma treatment. To prevent from oxidation under ambient conditions, immediately after plasma treatment, the FePt nanoparticle arrays were in situ transferred into the film-growth chamber where they were covered by an SiO2 overlayer. A nearly complete transformation of L10 FePt was achieved for samples annealed at temperatures above 700 °C. The well control on the FePt stoichiometry and avoidance from surface oxidation largely enhanced the coercivity, and a value as high as 10 kOe was obtained in this study. An evaluation of magnetic interactions was made using the so-called isothermal remanence (IRM) and dc-demagnetization (DCD) remanence curves and Kelly–Henkel plots (ΔM measurement). The ΔM measurement reveals that the resultant FePt nanoparticles exhibit a rather weak interparticle dipolar coupling, and the absence of interparticle exchange interaction suggests no significant particle agglomeration occurred during the post-annealing. Additionally, a slight parallel magnetic anisotropy was also observed. The results indicate the micellar method has a high potential in preparing FePt nanoparticle arrays used for ultrahigh density recording media.

FePt nanoparticles; Reverse micelles; Self-assembly; Interparticle exchange coupling; Magnetic recording