Room-temperature diluted magnetic semiconductors p- (Ga,Ni) N

High concentration (5 at. %) Ni was incorporated into a chemical vapor deposition-grown GaN film by using a thin protecting Ni layer on top of the GaN film during ion implantation. After etching off the protecting layer, subsequent annealing up to 800 °C under flowing N2 resulted in a p -type GaN with apparent ferromagnetic behavior up to ∼320 K. In addition, the ferromagnetic behavior became more manifest with increasing annealing temperature that increases hole concentration. No presence of any other second phases nor clusters in the Ni-implanted region was identifiable, at least to the 0.2 nm point-to-point resolution of high resolution transmission electron microscopy. This novel indirect implantation process that being easy to implement appears promising for attaining room-temperature diluted magnetic semiconductors which are applicable to magnetotransport, magneto-optical and spintronics devices, among others. © 2005 American Institute of Physics.