Carrier-mediated ferromagnetic ordering in Mn ion-implanted $p^{+}\mathrm{GaAs}:\mathrm{C}$

Highly p-type GaAs:C was ion implanted with Mn at differing doses to produce Mn concentrations in the 1–5 at. % range. In comparison to LT-GaAs and $n^{+}\mathrm{GaAs}:\mathrm{Si}$ samples implanted under the same conditions, transport and magnetic properties show marked differences. Transport measurements show anomalies, consistent with observed magnetic properties and with epi-LT-(Ga,Mn)As, as well as the extraordinary Hall effect up to the observed magnetic ordering temperature ${(T}_C).\mathrm{}$ Mn ion-implanted $p^{+}\mathrm{GaAs}:\mathrm{C}$ with as-grown carrier concentrations $>{10}^{20}{\mathrm{cm}}^{-3}$ show remanent magnetization up to 280 K.