Magnetic properties and microwave absorption properties of polymer-protected cobalt nanoparticles

Yoshihiro Kato, Satoshi Sugimoto, Ken Ichi Shinohara, Nobuki Tezuka, Toshio Kagotani, Koichiro Inomata

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

This paper describes magnetic properties and microwave absorption properties of polymer-protected cobalt nanoparticles. Cobalt nanoparticles were prepared using the thermal decomposition of dicobalt octacarbonyl in ethylene glycol. They were stabilized and dispersed by coexisting with poly(N-vinyl-2-pyrrolidone) (PVP), resulting in an average diameter of 45 mm. The X-ray diffraction (XRD) analysis revealed that the Co-PVP sample synthesized at 170°C for 3 h, with the mole ratio of cobalt: PVP = 1 : 10 (mol : unit mole), consisted of two phases of hcp and fcc cobalt. Their saturation magnetization measured using a vibrating sample magnetometer (VSM) was 1.53 × 10-4 Wb·m·kg-1. The compacted sample, produced from the PVP-protected cobalt nanoparticles, showed a reflection loss (R.L.) less than -20 dB at the frequency (matching frequency: fm) of 0.54 and 0.64 GHz with the thickness (matching thickness: dm) of 6.16 and 5.04 mm, respectively. Therefore, it is concluded that polymer-protected cobalt nanoparticles have a possibility for the use as microwave absorption materials.

Original languageEnglish
Pages (from-to)406-409
Number of pages4
JournalMaterials Transactions
Volume43
Issue number3
DOIs
Publication statusPublished - 2002 Mar

Keywords

  • Cobalt
  • Microwave absorber
  • Nanoparticles
  • Permeability
  • Polymer
  • Reflection loss

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Magnetic properties and microwave absorption properties of polymer-protected cobalt nanoparticles'. Together they form a unique fingerprint.

  • Cite this