Pure and iron with different concentrations (0.2, 1, 5, 10, 15, 20, 25, 30, 35 and 40 Mol. %) doped zinc oxide, symbolic as Zn: (0.2, 1, 5, 10, 15, 20, 25, 30, 35 and 40 Fe Mol. %) were synthesized using the self-modified sol–gel technique in powder form. Structural and morphological properties of the samples were studied comparatively by (XRD), (XPS), (FESEM), and (HRTEM), which revealed that the used samples adapted the hexagonal wurtzite structure. Some structural parameters such as strain, crystalline size, and dislocation density, were calculated to have accurate investigation giving rise to the nanostructure phase. The Laser-based Raman micro-spectroscopy presents the homogenous distribution of the iron oxide. The sensing performance of the samples toward the effect of increasing the temperature (from 25 to 150 °C) on the dielectric high-frequency range between 1 MHz up and 1 GHz was investigated with the help of a network impedance analyser (KEYSIGHT-E4991B). The mentioned increase in temperature record ε′ increases values while, it decreases by increasing the frequency, indicating a Debye-type dielectric dispersion. Compared to pure zinc oxide, an enhancement in both (σac) and the impedance real part Z′ was observed in the nanocomposite Z0.2F sample at higher dielectric temperature up to 130 °C. In contrast to pure ZnO, the area of the hysteresis loop against iron concentration for the doped samples increases with an increase in iron concentration. This behavior enhances ferromagnetism in Fe-doped ZnO nanostructure material.