Optical and magnetic properties of (Ga1-xMnx)N-based heterostructures

The optical and the magnetic properties of (Ga1-xMnx)N/GaN digital ferromagnetic heterostructures (DFHs) grown by using molecular beam epitaxy were investigated. The photoluminescence (PL) spectra showed band-edge exciton and exciton transitions between the conduction band and the Mn acceptor, indicative of the Mn atoms acting as substitutes, which corresponded to neutral donor-bound exciton for the GaMnN and GaN. The magnetization curves as functions of the magnetic field at 5 K indicated that the saturation magnetic moment in the (Ga1-xMnx)N/GaN DFHs decreased with increasing Mn mole fraction. The ferromagnetic properties of GaMnN/GaN DFHs were significantly affected by the hole concentration in the DFHs.