Enhancement of magnetic properties by nitrogen implantation to Mn-implanted p-type GaN

N and Mn ions were co-implanted into p-type GaN and subsequently annealed at 700–900 °C. Compared with Mn-implanted sample, the (Mn+N)-implanted sample revealed a larger ferromagnetic signal. This was attributed to the increase of Ga–Mn magnetic phases. Mn–N compounds, such as Mn6N2.58 and Mn3N2, decreased and the resistivity significantly increased, meaning a reduction of N vacancies. It is suggested that enhancement in ferromagnetic properties in the (Mn+N)-implanted GaN originated from the reduction of N vacancies and the increase of Ga–Mn magnetic phases.