Magnetodielectric study in SiO2-coated Fe3O 4 nanoparticle compacts

Chung Chieh Chang, Li Jing Zhao, Maw Kuen Wu

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

The dielectric properties of Fe3 O4 magnetic nanoparticles with an insulating coating layer of SiO2 were investigated. At high temperatures, the changes in the dielectric constant and loss induced by the magnetic field are opposite in sign and strongly frequency-dependent, which originates from extrinsic magnetodielectric coupling-the Maxwell-Wagner effect combined with magnetoresistance. And the interface defects leads to the obvious hysteresis phenomena observed in the measurements. On the other hand, the strong coupling of dielectric and magnetic properties at low temperatures contradicts the Maxwell-Wagner model, suggesting the intrinsic magnetodielectric coupling. Our observations are consistent with the recent polarization switching measurements, which confirm the low-temperature multiferroic state existing in highly lossy Fe3 O4. And the core/shell nanostructure may provide a new route to achieve applicable magnetoelectric materials with low loss.

Original languageEnglish
Article number094105
JournalJournal of Applied Physics
Volume108
Issue number9
DOIs
Publication statusPublished - Nov 1 2010
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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