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采用二次化学共沉淀法制备出六角或近六角片状BaFe_(12)O_(19),其颗粒径向尺寸和径厚比分别为0.4-2μm和4-20。通过XRD、FTIR、TG/DTA及SEM/EDS分析技术研究了片状BaFe_(12)O_(19)的形成历程。结果表明:前驱体为非晶态BaCO_3、低结晶态Fe(OH)_3和晶态α-Fe_2O_3包覆原料BaFe_(12)O_(19)复合物;前驱体在焙烧过程中经过Fe(OH)_3脱水、BaCO_3分解反应、中间相α-Fe_2O_3和BaO反应得到终产物BaFe_(12)O_(19)。基于形成历程,六角片状BaFe_(12)O_(19)较原料BaFe_(12)O_(19)表现出显著提高的颗粒径向尺寸和径厚比、较高的纯度和略低的结晶有序程度,进而表现出明显提高的矫顽力、略低的饱和磁化强度和剩余磁化强度。
The hexagonal or near-hexagonal flaky BaFe 12 O 19 was prepared by the second chemical coprecipitation method. The particle size and diameter-diameter ratio were 0.4-2μm and 4-20 respectively. The formation process of flaky BaFe_ (12) O_ (19) was investigated by XRD, FTIR, TG / DTA and SEM / EDS techniques. The results show that the precursors are BaFe_ (12) O_ (19) composite with amorphous BaCO_3, low crystalline Fe (OH) _3 and crystalline α-Fe_2O_3 coating. _3 dehydration, BaCO_3 decomposition reaction, mesophase α-Fe_2O_3 and BaO to get the final product BaFe_ (12) O_ (19). Based on the formation history, the hexagonal platelet BaFe 12 O 19 showed significantly higher particle size and diameter-diameter ratio, higher purity and slightly lower crystallographic ordering than BaFe 12 O 19. Degree, and then showed significantly improved coercivity, slightly lower saturation magnetization and residual magnetization.