| Abstract Scope |
High entropy oxides (HEO) have attracted significant attention due to their compositional complexity, structural stability, and multifunctional properties. In this study, spinel-structured (CoCrFeMnNi)<sub>3</sub>O<sub>4</sub> and rock-salt-structured (CoCuMgNiZn)O were synthesized via solution combustion synthesis (SCS) using nitrate-based precursors and different fuel systems (glycine, urea, citric acid). The effects of fuel type, fuel to oxidizer ratio, and post-calcination temperature on phase formation and microstructural evolution were systematically investigated. Calcination operations were conducted at 800°C, 900°C, and 1000°C to improve crystallinity and phase stability. The synthesized powders were characterized by X-ray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), and thermogravimetric analysis (TGA). The results demonstrated that combustion parameters strongly influence the reaction behavior, elemental homogeneity, and final crystal structure. This work highlights the versatility of SCS as an efficient and tunable route for the synthesis of homogeneous high-entropy oxide systems with distinct crystal structures. |