Structural and magnetic properties in mechanically alloyed Zn1−xCoxO semiconductor powders

Zn1−xCoxO (nominal x=5 and 30 at%) powders were prepared by mechanical alloying the binary oxides ZnO and CoO. The incorporation of Co element into the wurtzite structure with increasing milling times was followed by X-ray diffraction. Some basic properties of these bulk powder materials were investigated in order to contribute to the comprehension of the development of magnetism in these semiconductors. The change in optical properties with addition of Co was studied by photoluminescence and the corresponding magnetic properties were evaluated by field-cooling and zero-field-cooling magnetization measurements.