Influence of Miscut Angle on the Magnetoresistance Behavior of Epitaxial Fe3O4 Thin Films Grown on Vicinal Substrates

Abstract

This present work reported here the influence of miscut angle of vicinal MgO (100) substrates (with miscut angle between 1-5� along <011> direction) on the magnetoresistance (MR) behavior of epitaxial magnetite (Fe3O4) films. By varying the miscut angle, we are able to control the step-terrace periodicity of the substrate surface, which allows us to tailor the density of the step-edges induced antiphase boundaries, APBs (nanoscale liner defects formed during growth due to coalescence of neighbouring domains), in epitaxial Fe3O4 films. We found that the contribution from the step-edges induced APBs to the magnetoresistance (MRSE) in Fe3O4 films increases with increase in miscut (up to 2�) and decreases for larger miscut angles. From temperature dependent studies, we observed that the magnitude of MRSE increased with decrease in temperature and peaks at the Verwey transition. The decrease in MRSE for larger miscut samples is attributed to the influence of APB strain-fields on the degree of spin-polarization of Fe3O4 regions on terraces.