Characterization of High Dose Mn, Fe, and Ni implantation into p-GaN

Abstract

The magnetization of p-GaN or p-AlGaN/GaN superlattices was measured after implantation with high doses ${\text{(3–5×10}}^{16}$ ${\mathrm{cm}}^{\text{−2}})$ of Mn, Fe, or Ni and subsequent annealing at $\text{700–1000\hspace{0.05em}°}\mathrm{C}.$ The samples showed ferromagnetic contributions below temperatures ranging from 190–250 K for Mn to 45–185 K for Ni and 80–250 K for Fe. The use of superlattices to enhance the hole concentration did not produce any change in ferromagnetic ordering temperature. No secondary phase formation was observed by x-ray diffraction, transmission electron microscopy, or selected area diffraction pattern analysis for the doses we employed.