Properties investigation of GaN films implanted by Sm ions under different implantation and annealing conditions

Abstract

GaN films grown by MOCVD were implanted by Sm ions under different implantation and annealing conditions, in order to optimize the implantation parameters. The structural and magnetic measurements indicated a reduction of defect concentration and an increase of saturation magnetization when samples were implanted at 400°C, most probably due to the increased substitutional fraction of Sm ions. While the subsequent annealing process further decreased the damage in GaN lattice, but reduced the saturation magnetization on the contrary, caused by the decomposition of the surface layer and the formation of Sm-defect complexes during high-temperature annealing.