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 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. 
R. Farshchi, M. A. Scarpulla, P. R. Stone, K. M. Yu, I. D. Sharp, J.W.   Beeman, H. H. Silvestri, L.A. Reichertz, E.E. Halle...