Current-in-plane spin-valve magnetoresistance in ferromagnetic semiconductor (Ga,Fe)Sb heterostructures with high Curie temperature

TL;DR

This study demonstrates a current-in-plane spin-valve magnetoresistance effect in high Curie temperature ferromagnetic semiconductor heterostructures, highlighting interface scattering's role and potential for device applications.

Contribution

First demonstration of spin-valve magnetoresistance in Fe-doped ferromagnetic semiconductor heterostructures with high Curie temperature.

Findings

MR ratio increases as InAs layer thickness decreases.

Clear open minor loop observed at 3.7 K indicating magnetization switching.

Interface scattering enhances MR effect in thinner InAs layers.

Abstract

We demonstrate spin-valve magnetoresistance with a current-in-plane (CIP) configuration in (Ga,Fe)Sb / InAs (thickness $t_\mathrm{InAs}$ nm) / (Ga,Fe)Sb trilayer heterostructures, where (Ga,Fe)Sb is a ferromagnetic semiconductor (FMS) with high Curie temperature ($T_\mathrm{C}$). An MR curve with an open minor loop is clearly observed at 3.7 K in a sample with $t_\mathrm{InAs}$ = 3 nm, which originates from the parallel - antiparallel magnetization switching of the (Ga,Fe)Sb layers and spin-dependent scattering at the (Ga,Fe)Sb / InAs interfaces. The MR ratio increases (from 0.03 to 1.6%) with decreasing $t_\mathrm{InAs}$ (from 9 to 3 nm) due to the enhancement of the interface scattering. This is the first demonstration of the spin-valve effect in Fe-doped FMS heterostructures, paving the way for device applications of these high- $T_\mathrm{C}$ FMSs.