Impacts of Sr²⁺ and Annealing Temperature on the Composition, Structure, and Magnetic Properties of SrFe₁₂O₁₉ Synthesized by Tartrate Precursor Route

Hexagonal M-type strontium ferrite (SrFe12O19) has been fabricated through a simple self-combustion tartrate precursor approach to producing a homogenous powder with a homogeneous shape and limited size distribution at low-processing temperatures. The impacts of the Sr2+:Fe3+ molar ratio and the annealing temperature on formation, morphological structure, crystallite size, and magnetic performance were studied. The powders were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) profile, and vibrating sample magnetometer (VSM). The development of crystalline single-phase Sr-hexagonal ferrite occurred at >= 1100 degrees C and Sr2+:Fe3+ molar ratios 1.1:12-1.3:12. Existence of alpha-Fe2O3 and impurities in the hexagonal powders increases the lattice parameters while higher annealing temperature decreases it. The c/ a ratios of as-prepared samples (similar to 3.911-3.920) are comfortably within the range of ratios for M-type structures. The platelet-like structure has appeared at an annealing temperature >= 1000 degrees C. The wide saturation magnetization (37.26-66.19 emu/g) and coercivity (275.09-2107.8Oe) were accomplished at diverse synthesis conditions and reached the greatest values at 1350 degrees C. The squareness ratios (Mr/Ms) for all studied samples are <0.5, which is for multimagnetic domains.