Impact of Low Iron Doping on the Structural, Optical, and Magnetic Properties of Zinc Oxide Nanofilms for Spintronic Applications

Abstract

Films with varying compositions of Zn_1-xFe_xO (0 ≤ x ≤ 0.10) were produced using the sol–gel technique. The structural, optical, and magnetic studies were examined via “X-ray diffraction,” “EDX,” “UV–Vis spectrophotometer,” and “vibrating magnetometer.” The X-ray analysis data shows that all the films under examination have a hexagonal polycrystalline structure. As well, the crystallite size, D, reduced from 16.7 to 12.5 nm as the Fe ratio rose. The current findings show that the band gap, E_g^opt, is decreasing from 3.389 to 3.036 eV, suggesting the sp-d exchange that occurs between the s-p electrons of the valence and conduction bands and the d-electrons associated with the doped Fe³⁺ ions. Additionally, the refractive index, n, extinction coefficient, k_ex, and coefficient of Verdet, Vλ, as well the sheet resistance, R_s, and the figure of merit, φ, are estimated as a function of the doped Fe³⁺ ions ratio. Furthermore, the dispersion energy, E_d, increased from 11.476 to 11.906 eV, while the single oscillator energy, E_o, decreased from 6.72 to 6.063 eV. These results evidence that the incorporation of Fe into the ZnO lattice leads to the tunability of the optical properties. Finally, the measurements of magnetization exhibit a hysteresis loop in Fe-doped ZnO nanofilms, confirming the presence of room-temperature ferromagnetism. Making the Fe-doped ZnO films is suitable for use in optoelectronic and spintronic device applications.