Structural Evolution And Properties Of ZnO Film Prepared By Thermal Oxidation Under High Magnetic Filed

ZnO has attracted great interest for its wide band gap (3.37 eV) and relatively large exciton binding energy (60 meV) at room temperature. It has extensive application prospect in transparent electrode, gas sensing devices, piezoelectric devices because of its extensive sources and low-cost. Recently, there is little systematic research about nucleation mechanism and growth characteristics of ZnO films fabricated by different methods. Therefore, it is very important for improving the physical properties and controlling structures of films via study the growth behavior of ZnO fim.In this paper, the influence of oxidation temperature, time and film thickness on the structure and properties of ZnO film were investigated under a 6 T magnetic field. Furthermore, different high magnetic fields (6 T,8 T,12 T) were carried out. FE-SEM and AFM were used to detect the evolution of surface morphology. For the characterization of the crystal structure of the films, XRD measurements were performed. UV-vis-NIR spectrometer, VSM and four-probe were used to detect the optical, magnetic and electrical properties.Finally, the results of this paper were shown as follows:(1) Surface morphology of ZnO film fabricated by thermal oxidation is coral-like. The aggregation of partial of ZnO was reduced by a 6 T magnetic field. This phenomenon became significant at 500℃.(2) All samples showed a constant and high transmittance (about 80%) in visible and NIR regions and a high absorbance in the UV wavelength range, with a sharp fundamental absorption edge. At the same oxidation temperature, time and film thickness,6 T magnetic field can change the optical property of ZnO film.(3) Effects of different high magnetic fields on the structure and properties of ZnO films are different. No matter what high magnetic field is applied, the partial orientation growth of ZnO is inhibited. Then the transmittance in visible of ZnO film is reduced because of the increase of roughness.(4) Diffusion of Co atoms in the ZnO films was accelerated by a 6 T magnetic field. Therefore, the 6 T film has stronger room-temperature ferromagnetic behavior. The resistivity of the 6 T film is high at the range of 80-300 K.