Magnetodielectric phenomena in a charge- and spin-frustrated system of layered iron oxide

Makoto Naka, Aya Nagano, Sumio Ishihara

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Abstract

Dielectric and magnetic phenomena in spin- and charge-frustrated system R Fe2 O4 (R is a rare-earth metal ion) are studied. An electronic model for charge, spin, and orbital degrees in a pair of triangular-lattice planes is derived. We analyze this model by utilizing the mean-field approximation and the Monte Carlo simulation in a finite size cluster. A threefold-type charge-ordered structure with charge imbalance between the planes is stabilized in finite temperatures. This polar charge order is reinforced by spin ordering of Fe ions. This magnetodielectric phenomenon is caused by spin frustration and charge-spin coupling in the exchange interaction. We show cross-correlation effect in magnetic- and electric-field responses. Oxygen-deficiency effect as an impurity effect in a frustrated charge-spin coupled system is also examined.

Original languageEnglish
Article number224441
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume77
Issue number22
DOIs
Publication statusPublished - 2008 Jun 27
Externally publishedYes

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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