Influence of substrate pre-deposition annealing on step edges-induced magnetoresistance in epitaxial magnetite films grown on vicinal MgO (1 0 0) substrates

R. G S Sofin, S. K. Arora, I. V. Shvets

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3 Citations (Scopus)

Abstract

Magnetoresistance (MR) properties of epitaxial magnetite, Fe3O4, films grown on vicinal MgO (1 0 0) substrates show an enhancement and anisotropy in the MR in the direction across the step edges compared to the direction along the step edges. The observed enhancement in low-field MR response and MR anisotropy of epitaxial Fe3O4 films is explained by the enhanced spin scattering introduced due to the presence of atomic height steps, which leads to the formation of a greater number of antiphase boundaries (APBs) with out-of-plane shift vectors. We found that the optimum annealing duration required to observe maximum MR anisotropy is between 5 and 9 h. Longer annealing time leads to segregation of Ca impurities on the MgO surface which lead to a decrease in APB density and MR anisotropy.

Original languageEnglish
JournalJournal of Magnetism and Magnetic Materials
Volume316
Issue number2 SPEC. ISS.
DOIs
Publication statusPublished - Sep 2007

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Keywords

  • Magnetoresistance
  • Molecular beam epitaxy
  • Thin film
  • Verwey transition
  • Vicinal substrate

ASJC Scopus subject areas

  • Condensed Matter Physics

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