Room-temperature ferromagnetism of Cu-implanted GaN

1 MeV Cu2+ ion was implanted into GaN with a dose of 1×1017cm−2 at room temperature. After implantation, the samples were subsequently performed by rapid thermal annealing at 700, 800, and 900°C for 5min. Both nonmagnetic Cu ion implanted samples annealed at 700 and 800°C exhibit the ferromagnetism at room temperature, and the saturation magnetization of these samples is estimated to be 0.057μB and 0.27μB per Cu atom from M-H curve, respectively. However, the sample annealed at 900°C does not show ferromagnetism due to clustering of Cu during the annealing process.