Novel Quaternary Dilute Magnetic Semiconductor (Ga,Mn)(Bi,As): Magnetic and Magneto-Transport Investigations

K Levchenko,J Z Domagala,L Kowalczyk,M Szot,R Kuna,T Wosinski,T Figielski,T Andrearczyk,J Sadowski

doi:10.1007/s10948-016-3752-3

Abstract

Magnetic and magneto-transport properties of thin layers of the (Ga,Mn)(Bi,As) quaternary dilute magnetic semiconductor grown by the low-temperature molecular-beam epitaxy technique on GaAs substrates have been investigated. Ferromagnetic Curie temperature and magneto-crystalline anisotropy of the layers have been examined by using magneto-optical Kerr effect magnetometry and low-temperature magneto-transport measurements. Post-growth annealing treatment of the layers has been shown to enhance the hole concentration and Curie temperature in the layers. A significant increase in the magnitude of magneto-transport effects caused by incorporation of a small amount of Bi into the (Ga,Mn)As layers, revealed in the planar Hall effect (PHE) measurements, is interpreted as a result of enhanced spin-orbit coupling in the (Ga,Mn)(Bi,As) layers. A two-state behaviour of the planar Hall resistance at zero magnetic field provides its usefulness for applications in non-volatile memory devices.

Highlights

GaAs layers containing a few percent of Mn atoms became a model material among dilute magnetic semiconductors [1, 2]
Homogeneous layers of (Ga,Mn)As containing up to above 10 % of Mn atoms can be grown by a low-temperature (150–250 ◦C) molecular-beam epitaxy (LT-MBE) [3, 4]
We have recorded the magnetization hysteresis loops for the (Ga,Mn)As and (Ga,Mn)(Bi,As) layers by the magneto-optical Kerr effect (MOKE) measured as a function of magnetic field

Summary

Introduction

GaAs layers containing a few percent of Mn atoms became a model material among dilute magnetic semiconductors [1, 2]. Homogeneous layers with a high structural perfection of the (Ga,Mn)(Bi,As) quaternary dilute magnetic semiconductor, containing up to 6 % Mn and 1 % Bi, have been grown with LT-MBE under compressive misfit strain, on GaAs substrate [11, 12], as well as under tensile misfit strain, on (In,Ga)As buffer layer [13]. Their magnetic properties were similar to those of the ternary (Ga,Mn)As layers [14]. We report on magnetic and magneto-transport properties of thin epitaxial layers of the (Ga,Mn)(Bi,As) quaternary compound grown under compressive misfit strain, proving their usefulness for possible spintronic applications

Experimental

Results and Discussion

Conclusions