Tailoring the Structural, Optical and Magnetic Features of Nano ZnAl₂O₄ via Mn Doping

Zn 1-x Mn x Al 2 O 4 samples (x = 0.0, 0.3, 0.5 and 0.7) were formed via the solid-state reaction technique. Synchrotron X-ray diffraction technique was employed for precise quantification of phases developed and accurate determination of their structural parameters and cation distribution between the tetrahedral and octahedral sites, applying Rietveld refinement analysis. The solubility limit of Mn for present samples is high compared with literature. TEM (transmission electron microscopy) imaging is used to examine the particle shape and size of the prepared samples, and the chemical composition and surface morphology were inspected applying the scanning electron microscopy (SEM)/ energy dispersive X-ray spectroscopy (EDS) allow for targeted analysis of sample surfaces technique. Diffuse reflectance measurements manifested substantial reduction in the bandgap and enormous improvement in absorption following the incorporation of Mn, raising the doped specimens as challenging nominees for photocatalytic applications. The bandgap reduced to 1.66, 1.6, and 1.8 eV for Mn doping levels of x = 0.3, 0.5 and 0.7 respectively. The refractive index increased from 2.34 to 2.94 as the amount of Mn increased from 0 to 50%. The photoluminescence intensity is drastically quenched for all doping values of Mn. The values of linear and nonlinear optical parameters for ZnAl 2 O 4 generally grew with the presence of Mn. ZnAl 2 O 4 sample has a diamagnetic feature while the doped samples with Mn have paramagnetic behavior.