Annealing temperature effects on structural and magnetic properties of Ga 1−x Mn x N films

Amorphous gallium nitride doped with Mn thin films was deposited on sapphire (0001) substrates by laser molecular beam epitaxy. After simple processing of annealing at different temperatures for 30 min in ammonia atmosphere, good quality Ga_1−xMn_xN films were obtained. In order to investigate the influence of annealing temperature on the crystalline quality and structural and magnetic properties, the films are analysed by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy and alternating gradient magnetic field meter. The results show that the annealing can improve the quality of Ga_1−xMn_xN films, and the optimum annealing temperature is 1050°C; moreover, there is no second phase forming. Through magnetic analysis, we obtained the annealed samples of room temperature ferromagnetic property and paramagnetism of the as grown film and obtained the way of changing the paramagnetism into ferromagnetism using the simple method.