Influence of Step-edge induced antiphase boundary density on the magnetoresistance behavior of epitaxial Fe₃O₄ thin films

Abstract

We have studied the influence of step-edge (SE) induced antiphase-boundaries (APB) density on the magnetoresistance (MR) behavior of epitaxial magnetite (Fe₃O₄) films. The APB density was varied through the step-terrace periodicity of vicinal MgO (100) surface (miscut angle between 1 and 5°). The contribution from the SEs induced APBs on the MR, ΔMR, in Fe₃O₄ films increases with the decrease in temperature and peaks at the Verwey transition. Magnitude of the ΔMR is found to increase with miscut angle (up to 2°) and decreases for larger miscut angles, which is related to the influence of APB related strain-fields on the degree of spin-polarization of Fe₃O₄ regions on terraces.

Keywords:

• Magnetite
• vicinal surface
• magnetoresistance
• epitaxy

Additional information

Funding

The financial support from the Science Foundation Ireland is gratefully acknowledged (under contract no. 06/IN.1/191). The authors also would like to thank the DST for financial support under the PURSE-II grant.