Correlation between electrical transport, optical, and magnetic properties of transition metal ion doped ZnO

We report on the transport and optical properties of transition metal ions, namely Ti, V, Fe, Co and Ni doped ZnO samples. Diffuse reflectance spectroscopy of doped ZnO showed the existence of absorption bands which were attributed to the d-d transitions of respective dopants. Resistivity was found to decrease in the case of Ti, V, Fe, and Ni dopings. Correlation between the electrical resistivity and magnetic properties of the samples has been explained on the basis of impurity d-band splitting model.