Compositional tuning of ferromagnetism in Ga1−xMnxP

We report the magnetic and transport properties of Ga1−xMnxP synthesized via ion implantation followed by pulsed laser melting over a range of xx, namely 0.018–0.042. Like Ga1−xMnxAs, Ga1−xMnxP displays a monotonic increase of the ferromagnetic Curie temperature with xx 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 xx.