Unusual charge states and lattice sites of Fe in Al_xGa_1−xN:Mn

Abstract Charge states and lattice sites of Fe ions in virgin Mn-doped Al x Ga 1− N samples were investigated using 57 emission Mössbauer spectroscopy following radioactive Mn + ion implantation at ISOLDE, CERN. In the undoped N, 2+ on Al/Ga associated with nitrogen vacancies 3+ substitutional are identified. With doping, contribution is considerably reduced replaced instead by a corresponding emergence single-line-like component consistent 4+ sites. Density functional theory calculations confirm charge state as stabilised presence its vicinity. The completely filled spin up orbitals (3d 5 ) expected to enhance magnetic exchange interactions. population less pronounced high concentration N:Mn, behaviour attributable hybridisation effects 3d semiconductor bands which weakens increasing (decreasing) (Ga) content. Our results demonstrate that co-doping promotes co-existence unusual , whereas their trivalent prevail either transition metal incorporated independently III-nitrides. Co-doping thus opens new avenue for tailoring novel properties doped semiconductors.