Tailoring Magnetism of Perpendicularly Magnetized MnxGa Epitaxial Films on GaAs for Practical Applications

TL;DR

This study systematically investigates the growth, structure, and magnetic properties of MnxGa films on GaAs, demonstrating their potential for high-density magnetic recording and spintronic devices through effective magnetic property tailoring.

Contribution

First comprehensive analysis of MnxGa films on GaAs showing how composition and annealing influence magnetic properties for practical applications.

Findings

L10-ordered MnxGa films exhibit high coercivity and perpendicular anisotropy.

Films are thermally stable up to 450°C.

Magnetic properties can be tailored by post-growth annealing.

Abstract

MnxGa films with high perpendicular anisotropy, coercivity and energy product have great application potential in ultrahigh-density perpendicular recording, permanent magnets, spin-transfer-torque memory and oscillators, magneto-resistance sensors and ferromagnetic metal/semiconductor heterostructure devices. Here we present a comprehensive diagram of effective magnetism-tailoring of perpendicularly magnetized MnxGa films grown on III-V semiconductor GaAs by using molecular-beam epitaxy for the first time, by systematically investigating the wide-range composition and detailed post-growth annealing effects. We show that the (001)-orientated MnxGa films with L10 or D022 ordering could be crystallized on GaAs in a very wide composition range from x=0.76 to 2.6. L10-ordered MnxGa films show robust magnetization, high remanent ratio, giant perpendicular anisotropy, high intrinsic and extrinsic coercivity, and large energy product, which make this kind of material favorable for perpendicular magnetic recording, high-performance spintronic devices and permanent magnet applications. In contrast, D022-ordered films exhibit lower perpendicular anisotropy and weaker magnetism. Post-growth annealing MnxGa films studies reveal high thermal-stability up to 450 oC, and effective tailoring of magnetic properties can be realized by prolonging annealing at 450 oC. These results would be helpful for understanding this kind of material and designing new spintronic devices for specific practical applications.