Morphology and magnetic properties of barium hexaferrite ceramics synthesized in x wt% NaCl-(100-x) wt% KCL molten salts

摘要

Micron size barium hexaferrite (BaFe_(12)O_(19)) platelets were prepared by the molten-salt synthesis method in various weight proportions of NuCl-KCl salt mixtures as a liquid medium. The effect of molten salt composition-x wt% NaCl and (100-x) wt% KCl-on the amount of barum hexaferrite phase formation, as well as, on the morphology and magnetic properties of the final products are discussed. Inductively coupled plasma-mass spectroscopy (ICP-MS) was used to determine the solubility of the starting materials in the salts in order to understand the formation mechanism of barium hexaferrite. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) were used to identify the characteristics of the synthesized barium hexaferrite platelets. ICP-MS analysis showed that the Fe_2O_3 solubility is negligible, however, BaCO_3 has very high solubility in both molten KG and NaCl. Quantitative XRD and SEM results showed that molten salt containing 100 wt% NaCl at 900 °C (for 2 h) resulted in the highest production of barium hexaferrite. Further, SEM results showed that KCl-rich molten salt led to the formation of sharper faceted platelet morphology, whereas NaCl-rich ones resulted in more round platelets.