Effect of Heat Treatment on Structural and Magnetic Properties of Nanocrystalline SrFe12O19 Hexaferrite Synthesized by Co-Precipitation Method

Abstract

Article history : Nanocrystalline strontium hexaferrite (SrFe 12 O19 ) powders have been successfully synthesized using facile Co-preci pitation method. Ferrite precursors were obtained from mixtures of strontium and ferric chloride in an aqueous medium without any surfactant and soft template. The as-received powde rs were calcined at 800 and 1000 ˚C for 2 hours in air. The final powders were characterized by X-ray diffraction (XRD), scan ning electron microscopy (SEM), transmission electron microscopy (TEM), BET surface area analysis and Vibrating Sample Magnetometer (VSM). The effects of calcination temperature on phase com position, particle size and shape as well as magnetic propert ies of the products have been investigated. The results indica ted that higher calcination temperature (1000 o C) resulted in higher particle sizes (98.1 nm), maximum saturation magnetization (60.53 emu/g), remanence value (36.23 emu/g) and less surface area (12 m 2 g -1 ). The magnetocrystalline anisotropy constant, K, calc ulated from the Stoner-Wohlfarth theory, increases by increasing te mperature up to 15.1 (HA 2 /kg).