Influence of Fe doping on the optical and magnetic characteristics of RTA treated transparent zn_1-xFe_xO nanocrystalline films

Herein transparent Zn_1-xFe_xO nanocrystalline films have been prepared on glass substrates by sol-gel method followed by rapid thermal annealing treatment. The effecs of Fe doping on the microstructure, transmittance and magnetism of Zn_1-xFe_xO nanocrys-talline films are investigated. The x-ray diffraction patterns of all compositions show the same wurtzite hexagonal structure with the space group P6₃/mc. FE-SEM images show uniform spherical grains of all Zn_1-x Fe _xO nanocrystalline films in which the grain size decreases progressively from 38.85 nm (x = 0.00) to 15.35 nm (x = 0.04). Red shift of the absorption edges is obtained from the optical transmittance spectra from 372 nm of undoped ZnO film to 367 nm of Zn_0.96Fe_0.04O film. The corresponding wide band gap energy of undoped ZnO film is 3.2986 eV which decreases slightly by 0.0191 eV of Zn_0.96Fe _0.04O film. The saturation magnetization increases with the increase of Fe concentration. All Fe-doped ZnO films exhibit feromagnetic hysteresis curves which can be well fitted by the law of approaching to saturation with the formula, M = M _S (1 - a/H^m).