Magnetic property of Zn0.8CO0.2O Diluted Magnetic Semiconductors by Auto Combustion Method

Polycrystalline Zn0.8Co0.2O diluted magnetic semiconductors were synthesized by auto combustion technique from aqueous solutions of Zn and Co acetates using polyethylene glycol as catalyst. A complete series of Co (II) substituting Zn(II) was studied, from the structural point of view, by XRD and FTIR. The X-ray diffraction patterns of the films showed that the Co-doped ZnO powder exhibit wurtzite crystal structure. Magnetic hysteresis loops were observed at room temperature, indicating that ferromagnetism can be realized with Co doping into ZnO. Optical absorption measurements showed absorption bands indicating the presence of Co ions in substitution of Zn ions. The calculated band gap value of 2 at% Co doped samples was found to be around 3.37 eV. The morphology and crystalline size of the synthesized powders were evaluated by field emission scanning electron microscopy and transmission electron microscopy (TEM).