Synthesis and Characterization of Heterostructured Mn₃GaN_0.5/GaN Nanowires

Heterostructured Mn3GaN0.5/GaN nanowires have been synthesized by a catalytic chemical vapor deposition method. Mn3GaN0.5/GaN nanowires exhibit ferromagnetic properties with a Curie temperature above room temperature. It was observed that the acceptor Mn2+/Mn3+ (Mn 3d) levels superpose on the GaN energy levels, shifting the energy of 5.8 eV toward Fermi energy. Compared with GaN nanowires, the (DX)-X-0 line of Mn3GaN0.5/GaN at 397.8 nm (3.117 eV) indicated the 33.4 nm red-shift due to hole-doping in the PL spectra. The synthesized Mn3GaN0.5/GaN nanowires had the relatively high yellow band emission of about 596.5 nm, due to the internal T-4(1) -> (6)A(1) transition of Mn2+ (3d(5)), which is permitted by selection rules. The sharp peak at 675.6 nm in Mn3GaN0.5/GaN nanowire PL spectra might correspond to the transition T-4(2) -> defect state.