Structural and magnetic properties of Dy-implanted GaN films

GaN:Dy films were prepared by implanting Dy ions into c-plane (0001) GaN films and a subsequent rapid thermal annealing process. The structural and magnetic properties of samples were investigated by means of X-ray diffraction (XRD), Raman and Physical Property Measurement System (PPMS). The XRD and Raman studies showed that lattice damage and dislocation caused by ion implantation can be effectively recovered by rapid thermal annealing. The PPMS results showed ferromagnetism at room temperature. The average value of the moment per Dy ion (Ms/Dy) is increased after thermal annealing. The available vacancies and formation of bound magnetic poloron as a result of implantation and thermal annealing are assigned responsible for observed ferromagnetism.