Orientation degree dependence of magnetic properties of Co doped ZnO thin films by sol-gel process

Co-doped ZnO films were successfully fabricated on Si substrates by sol-gel process. The effects of Co concentration and preheating temperature on the structure and magnetic properties of the Zn_1-x Co _x O films were systematically studied. The results revealed that the films were highly c-axis oriented and contained no impurity phase. With preheating temperature increasing, the orientation degree of the films decreased. When the Co concentration and oxygen vacancy of the films are almost changeless, the enhancement of ferromagnetism in films originates from the orientation degree of the films increasing.