Field-dependent anisotropic magnetoresistance and planar Hall effect in epitaxial magnetite thin films

TL;DR

This study investigates the temperature and magnetic field dependence of anisotropic magnetoresistance and planar Hall effect in epitaxial magnetite thin films, revealing sign reversal and field dependence related to crystal symmetry.

Contribution

It provides a comprehensive analysis of AMR and PHE in magnetite films, emphasizing the importance of resistivity tensor determination in crystalline materials.

Findings

AMR and PHE depend on in-plane orientation consistent with cubic symmetry

AMR exhibits sign reversal as temperature varies

AMR shows significant field dependence without saturation up to 9 T

Abstract

A systematic study of the temperature and magnetic field dependence of the longitudinal and transverse resistivities of epitaxial thin films of magnetite (Fe3O4) is reported. The anisotropic magnetoresistance (AMR) and the planar Hall effect (PHE) are sensitive to the in-plane orientation of current and magnetization with respect to crystal axes in a way consistent with the cubic symmetry of the system. We also show that the AMR exhibit sign reversal as a function of temperature, and that it shows significant field dependence without saturation up to 9 T. Our results provide a unified description of the anisotropic magnetoresistance effects in epitaxial magnetite films and illustrate the need for a full determination of the resistivity tensor in crystalline systems.