| Article | |
| Title | Unusual charge states and lattice sites of Fe in Al$_{x}$Ga$_{1−x}$N:Mn |
| Author(s) | Masenda, Hilary (Witwatersrand U. ; Philipps U. Marburg) ; Gunnlaugsson, Haraldur Páll (Iceland U.) ; Adhikari, Rajdeep (Linz U.) ; Bharuth-Ram, Krish (DUT, Durban) ; Naidoo, Deena (Witwatersrand U.) ; Tarazaga Martín-Luengo, Aitana (Linz U.) ; Unzueta, Iraultza (Basque U., Bilbao) ; Mantovan, Roberto (CNR-IMM, Catania) ; Mølholt, Torben Esmann (CERN) ; Johnston, Karl (CERN) ; Schell, Juliana (CERN ; U. Duisburg-Essen) ; Mokhles Gerami, Adeleh (IPM, Tehran) ; Krastev, Petko (Sofiya, Inst. Nucl. Res.) ; Qi, Bingcui (Iceland U.) ; Ólafsson, Sveinn (Iceland U.) ; Gíslason, Haflidi Pétur (Iceland U.) ; Ernst, Arthur (Linz U. ; Halle, Max Planck Inst. Microstructure Phys.) ; Bonanni, Alberta (Linz U.) |
| Publication | 2022 |
| Number of pages | 12 |
| In: | New J. Phys. 24 (2022) 103007 |
| DOI | 10.1088/1367-2630/ac9499 |
| Abstract | Charge states and lattice sites of Fe ions in virgin and Mn-doped Al$_{x}$Ga$_{1−x}$N samples were investigated using $^{57}$Fe emission Mössbauer spectroscopy following radioactive $^{57}$Mn$^{+}$ ion implantation at ISOLDE, CERN. In the undoped Al$_{x}$Ga$_{1−x}$N, Fe$^{2+}$ on Al/Ga sites associated with nitrogen vacancies and Fe$^{3+}$ on substitutional Al/Ga sites are identified. With Mn doping, the contribution of Fe$^{3+}$ is considerably reduced and replaced instead by a corresponding emergence of a single-line-like component consistent with Fe$^{4+}$ on Al/Ga sites. Density functional theory calculations confirm the Fe$^{4+}$ charge state as stabilised by the presence of substitutional Mn$^{2+}$ in its vicinity. The completely filled spin up orbitals in Mn$^{2+}$ (3d$^{5}$) are expected to enhance magnetic exchange interactions. The population of the Fe$^{4+}$ state is less pronounced at high Al concentration in Al$_{x}$Ga$_{1−x}$N:Mn, a behaviour attributable to hybridisation effects of 3d states to the semiconductor bands which weakens with increasing (decreasing) Al (Ga) content. Our results demonstrate that co-doping promotes the co-existence of unusual charge states of Fe$^{4+}$ and Mn$^{2+}$, whereas their trivalent charge states prevail with either transition metal incorporated independently in III-nitrides. Co-doping thus opens up a new avenue for tailoring novel magnetic properties in doped semiconductors. |
| Copyright/License | publication: © 2022-2024 The Author(s) (License: CC-BY-4.0) |
Corresponding record in: Inspire
记录创建於2022-10-11，最後更新在2023-03-31
