Chemically synthesized L10-Type FePt nanoparticles and nanoparticle arrays via template-assisted self-assembly

Yuichi Sasaki, M. Mizuno, A. C.C. Yu, T. Miyauchi, D. Hasegawa, Tomoyuki Ogawa, M. Takahashi, B. Jeyadevan, Kazuyuki Tohji, K. Sato, S. Hisano

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Chemically ordered L10-type FePt nanoparticle agglomerates were synthesized directly by the co-reduction of Fe(III) and Pt(II) acetylacetonates in tetraethylene glycol at 300°C in the absence of surfactants. These nanoparticles could be dispersed in n-hexane by coating with oleic acid and oleylamine. However, the dispersed particles exhibited only chemically disordered fee phase and superparamagnetic behavior. The FePt nanoparticle film composed of dispersed particles and stabilized using amino-silane began to structurally transform to ordered L10 phase at 600°C, which is lower compared to that prepared by the hot soap method. Rotational hysteresis loss measurement suggested that the ordering was incomplete at 600°C and the nanoparticle film had the distribution of magnetocrystalline anisotropy field values. The FePt nanoparticle array was fabricated using the template-assisted self-assembly technique. To produce periodic dots on a substrate, positive-biased pulse voltage was applied to the substrate coated with octadecyltrichlorosilane monolayer by using a conducting cantilever used in a scanning probe microscope. This process induced electrochemical modification of -CH3 groups into polar ones. The resulting template had well-aligned sub-100-nm dot arrays with sub-100-nm periodicity. The FePt nanoparticles were fixed on the patterned areas selectively.

Original languageEnglish
Pages (from-to)660-664
Number of pages5
JournalIEEE Transactions on Magnetics
Volume41
Issue number2
DOIs
Publication statusPublished - 2005 Feb 1

Keywords

  • Dispersion
  • Electrochemical modification
  • FePt nanoparticle
  • L1 structure
  • Magnetic anisotropy field
  • Polycrystalline
  • Polyol process
  • Scanning probe lithography
  • Template-assisted self-assembly

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Chemically synthesized L1<sub>0</sub>-Type FePt nanoparticles and nanoparticle arrays via template-assisted self-assembly'. Together they form a unique fingerprint.

  • Cite this

    Sasaki, Y., Mizuno, M., Yu, A. C. C., Miyauchi, T., Hasegawa, D., Ogawa, T., Takahashi, M., Jeyadevan, B., Tohji, K., Sato, K., & Hisano, S. (2005). Chemically synthesized L10-Type FePt nanoparticles and nanoparticle arrays via template-assisted self-assembly. IEEE Transactions on Magnetics, 41(2), 660-664. https://doi.org/10.1109/TMAG.2004.838040