Ferromagnetic anisotropy in scandium-doped AlN hierarchical nanostructures

We experimentally fabricated uniformly distributed single-, double- and six-sided Sc-doped AlN (AlN:Sc) nanodendrites by a plasma-assisted direct current arc discharge method. The crystal structure, composition, morphological and microstructures were characterized, and the physical mechanisms governing the formation of AlN:Sc nanodendrites were examined. It was found that the morphology and the crystal orientation of the AlN nanodendrites can be controlled by tuning the N2 pressure. The incorporation of Sc induces native point defects in AlN that contribute to the growth of hierarchical structures and affect the room-temperature photoluminescence. The AlN:Sc nanodendrites exhibit room-temperature anisotropic ferromagnetism, and this is strongly depend on the orientation of the nanodendrites. This work provides a facile strategy to fabricate complex hierarchical AlN:Sc nanostructures with manipulated magnetic properties which may find promising applications in spintronic nanodevices.