Effects of Annealing Temperature and Dopant Concentration on the Structural, Optical, and Magnetic Properties of Iron-Doped ZnO Samples

Abstract

This paper reports on the structural, optical, and magnetic properties of as-prepared and annealed Zn 1-x Fe x O (0.02≤x≤0.08) powders synthesized using the solid-state reaction method. X-ray diffraction (XRD) studies showed that Fe was incorporated into the ZnO lattice. Ultraviolet-Visible (UV-vis) spectrophotometry measurements revealed that the bandgap initially increased and then decreased with Fe doping. Photoluminescence (PL) studies confirmed the formation of oxygen vacancies (V O) in all of the samples. All of the samples exhibited ferromagnetic behavior at room temperature (RT). Ferromagnetic behavior decreased with increased Fe concentrations, due to the increase in the number of Fe atoms occupying the neighboring cation lattice sites, which resulted in an antiferromagnetic configuration. Ferromagnetic behavior also decreased with the increase in the annealing temperature (T A) due to the reduction of defects and/or V O. However, our results indicate that the ferromagnetic property is intrinsic to the ZnO system due to defects and/or V O , and the extrinsic impurity origin was excluded..