UC Riverside

Transition metal doped ZnO has been proposed to be a Diluted Magnetic Semiconductor with room temperature ferromagnetism. High quality Mn doped ZnO was grown on R-sapphire substrate. Results support intrinsic ferromagnetism, while µB/ion number was found to be larger than maximum permitted by Hund's law. Saturation strength and coercivity field was found to be manipulated by varying Mn doping concentration. Mn/Ag co-doping was found to alter saturation strength and coercivity field as well. Ag was investigated as substitution dopant to achieve high quality p-type ZnO. With optimization of growth parameters, phase segregation was suppressed and p-type was observed. Besides being p-type, Ag doped ZnO was found to exhibit room temperature ferromagnetism. This is the first high quality demonstration of Ag doped ZnO as DMS.