Preparation and characterization of nanocrystalline barium ferrite ceramic

摘要

In this work, nanocrystalline BaFe12O19 hexaferrite ceramic was synthesized via high-energy ball milling and subsequent sintering from the mixed powders of Fe2O3 and BaCO3. X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS), differential thermal analysis (DTA) and scanning electron microscopy (SEM) were utilized to understand the structural evolution during the synthesis process. Vibrating sample magnetometer (VSM) was also used to investigate the magnetic properties of the samples as a function of sintering process. DTA analysis suggested that the initial high-energy milling of the precursors helps the formation of single domain magnetic particles. According to the results obtained, BaFe12O19 can be formed via two main steps, during which BaFe2O4 is formed initially that eventually turns into BaFe12O19. VSM-based findings showed that the ratio of remanent magnetization to magnetization value (Mr/Ms) is around 0.5 which is the expected value for randomly oriented assembly of uniaxial single-domain particles undergoing magnetization reversal by coherent rotation. The observed magnetic parameters (Mr and Ms) are much higher than the previously reported values, due to the reduction in particle size as a result of ball milling.