Abstract
Abstract
In this research, Manganese aluminate (MA), Nickel aluminate (NA), and Zinc aluminate (ZA) nanocrystallites were synthesized using the combustion method at a temperature of 1173 K. This technique was selected for its effectiveness in producing nanocrystalline materials with high purity and precise compositional control. The synthesized nanocrystallites underwent extensive characterization to understand their structural and optical properties. Techniques such as UV–visible spectrophotometry (UV–vis), Fourier-transform infrared spectroscopy (FT-IR), and x-ray diffraction (XRD) were utilized to examine the impact of different cations (Mn2+, Ni2+, Zn2+) on the optical bandgap, binding energy, and crystallographic parameters of the materials. The optical bandgap values (Eg), determined using Tauc’s formula, were 4.121 eV for manganese aluminate, 3.819 eV for nickel aluminate, and 3.771 eV for zinc aluminate. FT-IR spectroscopy identified fundamental absorption peaks within the range of 450 to 750 cm−1, confirming the formation of aluminate spinel structures. XRD analysis confirmed the presence of a cubic spinel-type structure in all three prepared samples. The results revealed that the average crystallite sizes ranged from 23.890 nm to 45.100 nm, cell volumes varied between 521.47 Å3 and 548.68 Å3, lattice constants spanned from 8.258 Å to 8.049 Å, and inter-planar spacing ranged from 2.4268 nm to 2.4532 nm. These variations were observed as the cation transitioned from nickel to manganese passing through zinc element. Additionally, Rietveld refinements were performed to further analyze and refine the crystal structures based on XRD data. This comprehensive study aimed to elucidate the relationship between the synthesis conditions and the resultant properties of the nanocrystallites, providing insights into their potential applications in fields such as optoelectronics and photocatalysis.