Pristine ZnO and iron-doped ZnO (x = 0, 0.04, 0.08, 0.10, and 0.15) nanoparticles were produced by means of precipitation route. The nanoparticles were subjected to thermogravimetric analysis. Both EDX and XPS were employed to analyze the chemical structure of samples. The XRD pattern shows that the hexagonal structure of iron-doped ZnO nanoparticles is known, and this suggests that Fe2 + can substitute Zn2 + in the lattice of ZnO without the discovery of another precipitated phase. As the amount of Fe material increases, the lattice strain rises from 0.0277 to 0.0379, even though a crystallite size falls from 38 to 28 nm, x is equal 0, and 0.15, respectively. The only factors that significantly affect the shrinking of crystallite size are preparation conditions and structural disorder. In terms of UV–vis absorption spectroscopy, the energy gap, Egopt\documentclass[12pt]{minimal}
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\begin{document}$$E_{g}^{opt}$$\end{document} value obtained from the derivative of absorbance concerning wavelength and found to be reduced from 3.41 eV when x of around 0 and 3.1 eV when x of around 0.15 with rising Fe content. The photoluminescence spectrometry can produce wide PL peaks because of the numerous recombination faults and sites. The presence of additional peaks from an intrinsic emission is thought to be the cause of the PL's asymmetric spectrum. The M-H measurements demonstrated RT ferromagnetism in the Fe-doped ZnO nanoparticles by vibrating the sample in a magnetometer. Additionally, the coercive field increases from 59.9 G to 85.3 G and the remanent magnetization increases from 3.4 × 10–3 to 21 × 10–3 emu/g when the iron content rises from (x of around 0.02) to (x of around 0.15). By improving the magnetic and optical properties of samples, these findings enable the use of iron-doped ZnO nanoparticles in optoelectronic and spintronic applications.