Structural, optical ellipsometry, and magnetic characteristics of iron-doped zinc oxide thin films for spintronic applications

Zn_1−xFe_xO films with x = 0, 5, 10, 15 and 20% at. were created using an electron beam gun and high vacuum. It has been considered how the concentration of Fe doping will affect the films' structural, magnetic and optical properties. All films' XRD signals at different Fe concentrations revealed wurtzite-type structures. The results demonstrate that when Fe content increases, the size of nano-films decreases from 24 nm (%) to 11 nm (0.20%). This results from the distinction between Zn's and Fe's ionic radii. The XPS spectra showed peaks related to the components to be observed for precipitated 10% Zn_1−xFe_xO nanoparticles and undoped ZnO nanoparticles: zinc (Zn), iron (Fe), and oxygen (O). By using SE measurements, the optical constants (n, k) of the Zn_1−xFe_xO films were determined use an ellipsometry model, allowing for the verification of the Fe³⁺ ions in Fe-doped ZnO. With the addition of Fe, from 3.44 to 3.28 eV, the energy band gap shrunk. Zn_1−xFe_xO thin film was found to have ferromagnetism at normal temperature by M-H tests. As the Fe concentration rises, the magnetization increases until it reaches a concentration of 15%, at which point it starts to decrease. This decrease in magnetization was attributable to the spinel phase, which was seen in the XRD spectra. These findings imply that Zn_1−xFe_xO is a highly suggested material for the creation of spintronic and optoelectronic devices.