Effect of temperature on the magnetic properties of strontium hexaferrite synthesized by the Pechini method

Abstract

In this work, strontium hexaferrite powders were synthesized by the polymeric complex method (Pechini). The as-prepared samples were calcined at temperatures of 800 °C, 850 °C, 900 °C, 1000 °C, and 1050 °C for 1 h. In addition, the presence of a secondary phase of hematite (α-Fe2O3) was detected in all samples. The influence of calcination temperature and synthesis technique to control grain growth and size was analyzed. The crystalline phases, structure and morphology of the samples were determined by X-ray diffraction, scanning electron microscope and transmission electron microscopy. While the magnetic properties were measured at room temperature using a vibrating sample magnetometer with an applied field of up to 20 KOe. The results show that the sample calcined at 900 °C with a crystal size of 245 nm exhibits the best magnetic properties of the entire series, obtaining the highest values of magnetization by saturation and coercivity (Ms 99.3 emu/g, and Hc 6.15 kOe). This can be attributed to the exchange coupling interactions between the soft and hard phases of the sample.