Magnetic and electric properties of transition-metal-doped ZnO films

3d-transition-metal-doped ZnO films (n-type Zn1-xMxO (x=0.05-0.25): M=Co, Mn, Cr, Ni) are formed on sapphire substrates using a pulsed-laser deposition technique, and their magnetic and electric properties are examined. The Co-doped ZnO films showed the maximum solubility limit. Some of the Co-doped ZnO films exhibit ferromagnetic behaviors with the Curie temperature higher than room temperature. The magnetic properties of Co-doped ZnO films depend on the concentration of Co ions and carriers. (C) 2001 American Institute of Physics.