Room-temperature diluted magnetic semiconductors p-(Ga,Ni)N -: art. no. 202507

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 degrees C under flowing N-2 resulted in a p-type GaN with apparent ferromagnetic behavior up to similar 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. (C) 2005 American Institute of Physics.