Zn0.96-xCu0.04FexO (0 ≤ x ≤ 0.04) alloys - Optical and structural studies

Undoped and Fe doped Zn0.96Cu0.04O (Fe = 0.01, 0.02, 0.03 and 0.04) alloys were successfully synthesized by sol-gel method. The hexagonal wurtzite structure of ZnO could not altered by Cu and Fe doping and it was confirmed by X-ray diffraction spectra. The initial non-equilibrium substitution of Fe (0.01) led to increase the lattice parameters such as d-value, cell parameters, volume and bond length. But the lattice parameters were decreased after Fe = 0.01 due to the proper substitution of Fe3+ ions. The changes in lattice parameters, average crystal size, peak position and peak intensity confirmed the Fe substitution into Zn-Cu-O lattice. The change in surface morphology by Fe doping was studied by scanning electron microscope. The observed linear decrease of energy gap, red shift was explained by the sp-d spin exchange interaction of band electron with the d-electron of Fe. Presence of chemical bonding was confirmed by FTIR spectra. (c) 2014 Elsevier Ltd. All rights reserved.