Effect of gamma irradiation on optical, magnetic and structural properties of AgMnFe₂O₄ nanoparticles

Tailoring the structure, particle size, and morphology of nanoparticles to optimize their optical and photocatalytic performance has recently attracted considerable attention. Manganese and silver nanoferrites, owing to their distinctive physical properties, are promising materials for such applications. In this study, Silver-modified manganese ferrite nanocomposites (AgMnFe₂O₄) were successfully synthesized by a single-step solvothermal method and subsequently subjected to high-dose gamma irradiation. The morphology, crystal structure, magnetic behavior, and optical properties of unirradiated and irradiated samples were investigated using field emission-scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Vibrating Sample Magnetometer (VSM), Fourier transform infrared (FTIR), and UV-visible spectrophotometer (UV-vis). FE-SEM analysis revealed noticeable irradiation-induced changes in the particle size and morphology. The crystallite size (D), lattice strain (ε), and dislocation density (δ) were evaluated using the Scherrer and Williamson-Hall (W-H) methods, confirming that gamma irradiation induced a significant increase in lattice strain and structural disorder. VSM analysis showed that irradiation led to a marked decrease in the saturation magnetization of AgMnFe₂O₄ nanoparticles. Furthermore, optical analysis indicated an increase in the optical bandgap after irradiation, accompanied by improved photocatalytic efficiency compared with the unirradiated sample. These findings suggest AgMnFe₂O₄ nanoparticles are promising candidates for photocatalytic applications under UV irradiation.