Magnetic field controllable planar Hall effect in Sr2IrO4 films

Abstract

The planar Hall effect (PHE) has remarkable advantages for applications to spintronic devices and the study of intrinsic magnetic properties because of its high signal-to-noise ratio and low thermal drift. Here, the magnetic field controllable PHE in ${\mathrm{Sr}}_{2}\mathrm{Ir}{\mathrm{O}}_{4}/\mathrm{SrTi}{\mathrm{O}}_{3}$ (001) films is presented. The PHE transforms from a ``sinusoidal-shaped'' twofold symmetry to fourfold oscillations with decrease in the magnetic field at 35 K. Furthermore, the PHE is approximately two to three orders of magnitude larger than the giant PHE associated with ferromagnetic semiconductors as the temperature decreases. Based on subsequent measurements of the magnetic transport properties and calculations of the angle between the magnetization and current, the unexpected fourfold-symmetric PHE can be attributed to magnetocrystalline anisotropy and spin-orbital coupling. These observations of PHE facilitate a deeper understanding of the magnetic interactions in ${\mathrm{Sr}}_{2}\mathrm{Ir}{\mathrm{O}}_{4}$ films and indicate potential applications in spintronic or magnetic-sensor devices.