Solution Combustion Synthesis and Characterization of (CoCrFeMnNi) 3 O 4 High-Entropy Oxide Using Different Fuels

High Resolution Image Download MS PowerPoint Slide High-entropy oxides (HEOs) have recently attracted significant interest due to their tunable crystal structures, compositional versatility, and promising functional properties in energy storage, catalysis, and magnetic applications. Among various synthesis routes, solution combustion synthesis (SCS) offers a rapid and energy-efficient pathway for producing phase-pure HEO powders with controlled morphology. In this study, (CoCrFeMnNi) 3 O 4 high-entropy oxide was synthesized via SCS using three different fuels, followed by postcombustion heat treatments at 800, 900, and 1000 °C for 1 h. The calcination temperatures were selected based on thermogravimetric analysis (TGA) and literature data. Phase formation, microstructural evolution, and elemental distribution were investigated by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS), while specific surface area and porosity characteristics of selected samples were evaluated by Brunauer–Emmett–Teller (BET) analysis and its corresponding Barrett–Joyner–Halenda (BJH) method. The results revealed that the choice of fuel significantly influenced the combustion characteristics, phase purity, and particle morphology, while the calcination temperature played a key role in grain growth and densification. Glycine at a stoichiometric ratio (Φ e = 1) and calcination at 900 °C yielded the most favorable results, producing sharp spinel peaks consistent with the F d 3 − m space group and elemental distributions closest to equimolar. TGA confirmed high thermal stability with