Tunable Planar Hall Effect in (Ga,Mn)(Bi,As) Epitaxial Layers.

Tomasz Andrearczyk,Tadeusz Figielski,Janusz Sadowski,Jerzy Wróbel,Tadeusz Wosinski

doi:10.3390/ma14164483

Tomasz Andrearczyk, Tadeusz Figielski + Show 3 more

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https://doi.org/10.3390/ma14164483

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Abstract

We have thoroughly investigated the planar Hall effect (PHE) in the epitaxial layers of the quaternary compound (Ga,Mn)(Bi,As). The addition of a small amount of heavy Bi atoms to the prototype dilute ferromagnetic semiconductor (Ga,Mn)As enhances significantly the spin–orbit coupling strength in its valence band, which essentially modifies certain magnetoelectric properties of the material. Our investigations demonstrate that an addition of just 1% Bi atomic fraction, substituting As atoms in the (Ga,Mn)As crystal lattice, causes an increase in the PHE magnitude by a factor of 2.5. Moreover, Bi incorporation into the layers strongly enhances their coercive fields and uniaxial magneto-crystalline anisotropy between the in-plane 〈110〉 crystallographic directions in the layers grown under a compressive misfit strain. The displayed two-state behaviour of the PHE resistivity at zero magnetic field, which may be tuned by the control of applied field orientation, could be useful for application in spintronic devices, such as nonvolatile memory elements.

Highlights

In the quest for more efficient spintronic materials, which are both useful for spintronic applications and interesting for physical phenomena investigations, we have focused on the quaternary (Ga,Mn)(Bi,As) compound [1,2]
Our early measurements, performed by means of a modulation photoreflectance spectroscopy method [6], revealed that an addition of only 0.3% Bi atoms substituting As atoms in the (Ga,Mn)As crystal lattice caused a distinct modification of its valence band [1]
It is worth noting that the planar Hall effect (PHE) resistivity record registered while sweeping a magis worth that resistivity record registered sweeping a magnetic neticItfield maynoting depend onthe thePHE

Summary

Introduction

In the quest for more efficient spintronic materials, which are both useful for spintronic applications and interesting for physical phenomena investigations, we have focused on the quaternary (Ga,Mn)(Bi,As) compound [1,2]. Our early measurements, performed by means of a modulation photoreflectance spectroscopy method [6], revealed that an addition of only 0.3% Bi atoms substituting As atoms in the (Ga,Mn)As crystal lattice caused a distinct modification of its valence band [1]. It results in a significant increase in the magnitude of magnetotransport effects, as evidenced by our recent experiments performed for (Ga,Mn)(Bi,As) layers containing up to 1% Bi atomic fraction [7,8].

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