Irradiation-induced defects recovery and magnetic property of the Gd ion implanted GaN

Yabuuchi, Atsushi; Maekawa, Masaki; Kawasuso, Atsuo; Hasegawa, Shigehiko*; Zhou, Y.-K.*; Asahi, Hajime*

Recent GaN-based DMS studies have reported that Gd-doped GaN tend to indicate large magnetization in defective films. In addition, recent theoretical calculation study has also reported that a presence of vacancies affects the magnetic properties in DMS. In this study, Gd ions were implanted into MOCVD-GaN film by using ion implantation techniques. Furthermore, we have attempted to clarify the correlation between the magnetic properties and presence of vacancy-type defects. As a result, irradiation-induced defects have decreased greatly at 1000 C annealing. However, vacancy-type defects were still remained after 1300 C annealing. Alternating gradient magnetometer (AGM) measurements were also performed at room temperature for the unimplanted, as-implanted and post-implanted 1300 C annealed GaN films. However, clear magnetic hystereses were not observed even in the as-implanted film. In further study, high temperature ion implantation experiments are needed.