Co-doped ZnO films were fabricated using a pulsed laser deposition method on

c

-sapphire substrates. The structural and magnetic properties of the Co-doped ZnO films have been studied in this paper. The XRD characterization results show that they are wurtzite structures with the

c

-axes of the films aligning with those of the substrates. However the films do not grow along with the same orientation on the whole area of the specimens based on the HRTEM results. It is hard to conclude that the films were formed to be single crystals. The results reveal the occupation of Co ions at Zn sites in the host lattice. The studies of the electronic structures of the thin films show that the addition of Co ions into the Zn sites in the host ZnO affects the electronic band structure of the material. Magnetic hysteresis loops (M-H) were observed at room temperature

suggesting that the magnetism could be realized by Co-doping into ZnO. However

the improvement is limited. The work is following our previous reports on ZnO based diluted magnetic semiconductors

in which Co-doped ZnO thin films were synthesized using a dual-beam pulsed laser deposition method

suggesting their intrinsic mechanisms involved are probably similar.