Magnetic Nanocomposites at Microwave Frequencies

  • Jaakko V.I. Timonen
  • Robin H.A. Ras
  • Olli Ikkala
  • Markku Oksanen
  • Eira Seppälä
  • Khattiya Chalapat
  • Jian Li
  • Gheorghe Sorin Poraoanu
Chapter
Part of the Engineering Materials book series (ENG.MAT.)

Abstract

Most conventional magnetic materials used in the electronic devices are ferrites, which are composed of micrometer-size grains. But ferrites have small saturation magnetization, therefore the performance at GHz frequencies is rather poor. That is why functionalized nanocomposites comprising magnetic nanoparticles (e.g. composed of Fe, Co) with dimensions ranging from a few nm to 100 nm, and embedded in dielectric matrices (e.g. silicon oxide, aluminium oxide) have a significant potential for the electronics industry. When the size of the nanoparticles is smaller than the critical size for multidomain formation, these nanocomposites can be regarded as an ensemble of particles in single-domain states and the losses (due for example to eddy currents) are expected to be relatively small.

Here we review the theory of magnetism in such materials, and we present a novel measurement method used for the characterization of the electromagnetic properties of composites with nanomagnetic insertions. We also present a few experimental results obtained on composites consisting of iron nanoparticles in a dielectric matrix.

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Copyright information

© Springer –Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Jaakko V.I. Timonen
    • 1
  • Robin H.A. Ras
    • 1
  • Olli Ikkala
    • 1
  • Markku Oksanen
    • 2
  • Eira Seppälä
    • 2
  • Khattiya Chalapat
    • 3
  • Jian Li
    • 3
  • Gheorghe Sorin Poraoanu
    • 3
  1. 1.Molecular Materials, Department of Applied Physics, School of Science and TechnologyAalto UniversityAaltoFinland
  2. 2.Nokia Research CenterHelsinkiFinland
  3. 3.Low Temperature Laboratory, School of Science and TechnologyAalto UniversityAaltoFinland

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