Investigation on structural and nonlinear optical properties of Al and Cu doped ZnFe2O4 nanoparticles

Copper and aluminum substituted ZnFe2O4 [Zn1–x–yCuxAlyFe2O4 (x and y = 0, 0.05, 0.15, and 0.25)] nanoparticles were prepared by microwave combustion technique. The crystal structures were confirmed by x-ray techniques, and the sizes ranged from 11 to 25 nm of copper and aluminum doped ZnFe2O4. The stretching frequencies are displayed by FT-IR spectra. The bandgap range is between 1.97 and 1.88 eV with substituting concentrations of Al3+ and Cu2+, which is due to the calculation by the Kubelka–Munk formula and the formation of sub-bands. The morphology was displayed by FE-SEM analysis. The EDX spectrum showed the elements of Zn, Al, Cu, Fe, and O. M–H loops showed that ZnFe2O4 has diamagnetism, where copper and aluminum doped ZnFe2O4 has ferromagnetic behavior. The nonlinear absorption coefficient (10−4 cm/W), susceptibility (10−6 esu), and refraction (10−8 cm2/W) were observed by Z-scan techniques. The optical limiting analyses confirm that these samples are feasible candidates for the development of optical devices, power limiters, and switches.