Compositional tuning of ferromagnetism in Ga1-xMnxP

TL;DR

This study explores how the ferromagnetic properties of Ga1-xMnxP can be tuned through compositional changes, revealing a correlation between Mn content, Curie temperature, and transport mechanisms, with implications for spintronic materials.

Contribution

It demonstrates the compositional tuning of ferromagnetism in Ga1-xMnxP and compares its properties to Ga1-xMnxAs, highlighting unique non-metallic behavior and transport mechanisms.

Findings

Curie temperature increases with Mn content

Ferromagnetism quenched by thermal annealing above 300°C

Transport occurs via hopping conduction at low temperatures

Abstract

We report the magnetic and transport properties of Ga1-xMnxP synthesized via ion implantation followed by pulsed laser melting over a range of x, namely 0.018 to 0.042. Like Ga1-xMnxAs, Ga1-xMnxP displays a monotonic increase of the ferromagnetic Curie temperature with x associated with the hole-mediated ferromagnetic phase while thermal annealing above 300 C leads to a quenching of ferromagnetism that is accompanied by a reduction of the substitutional fraction of Mn. However, contrary to observations in Ga1-xMnxAs, Ga1-xMnxP is non-metallic over the entire composition range. At the lower temperatures over which the films are ferromagnetic, hole transport occurs via hopping conduction in a Mn-derived band; at higher temperatures it arises from holes in the valence band which are thermally excited across an energy gap that shrinks with x.