Sintering temperature dependence of optimized microstructure formation of BaFe_(12)O_(19) using sol-gel method

摘要

In an attempt to obtain the best possible properties of barium hexaferrite (BaFe_(12)O_(19)), the sol-gel synthesis method was chosen and, the optimum sintering conditions were established. The effects of the sintering temperature on the structural, morphological and magnetic properties of hexaferrite were studied. X-ray analysis indicates that the sintered samples (1,000-1,150 ℃) remained in the hexagonal structure. From this analysis, no secondary phases are identified. The effect of sintering temperature on the grain growth of BaFe_(12)O_(19) is confirmed by the microstructure using HR-SEM and is in good agreement with the XRD analysis based on the peak intensity of the (107) plane. The samples sintered at 1,150 ℃ showed the densities as ～93 % of theoretical density. Sintering temperature affected the grains in compact samples. The results show that homogeneous and dense BaFe_(12)O_(19) ceramics obtained at a lower sintering temperature of 1,150 ℃ which is lower than the normally reported sintering temperature of ≥ 1,200 ℃. The thermal treatment can markedly affect the grains in compact samples.