Synthesis and characterization of nanostructured magnetoresistive Ni doped ZnO films

We report a method to produce magnetic nanostructured semiconductor films based in ZnO doped with Nickel to control their magnetic properties. The method is based on a combined diffusion-oxidation process within a controlled atmosphere chamber to produce a uniform distribution of Ni ions in the ZnO films (ZnO:Ni). The synthesis of ZnO:Ni films is reported as well as the magnetoresistive characteristics, the used method yields films with reproducible and homogeneous properties. The films were also characterized structurally by X-Ray Diffraction (XRD) and Raman spectroscopy, and by Hall-van der Pauw measurements. The XRD measurements confirm the nanocrystalline films character. The films resulted of n-type conductivity with electron concentrations of ∼10²⁰ cm^-3 in average and carrier mobilities of 5 cm²/V s. The Magnetoresistance (MR) behavior of the films at 300 K shows negative changes of ΔR∼0.5% in accordance with the usual literature reports on samples produced by other methods.