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

TL;DR

This study investigates the magnetic and magneto-transport properties of a new quaternary dilute magnetic semiconductor, (Ga,Mn)(Bi,As), revealing enhanced effects due to Bi incorporation and potential for nonvolatile memory applications.

Contribution

It introduces a novel (Ga,Mn)(Bi,As) material with improved magnetic and transport properties, demonstrating the effects of Bi incorporation and annealing on Curie temperature and spin-orbit coupling.

Findings

Bi incorporation enhances magnetotransport effects.

Postgrowth annealing increases Curie temperature.

Two-state planar Hall resistance suggests memory device potential.

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. Postgrowth annealing treatment has been shown to enhance the hole concentration and Curie temperature in the layers. Significant increase in the magnitude of magnetotransport 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. Two-state behaviour of the planar Hall resistance at zero magnetic field provides its usefulness for applications in nonvolatile memory devices.