Bi_2O_3对低烧Co-Ti替代钡铁氧体显微结构与高频磁性的影响

Effects of Bi2O3 doping on the mcrostructure and high-frequency magnetic properties of low-temperature sintered Co-Ti substituted barium ferrites

用化学共沉淀法制备了Co-Ti替代钡铁氧体磁粉,结合相结构与显微形貌分析研究了Bi2O3掺杂和Co-Ti替代量对低温烧结钡铁氧体高频磁性的影响。Bi2O3的加入明显提高了低温烧结钡铁氧体的磁导率,磁粉粒径在200nm左右时合适的Bi2O3添加量为2％(质量分数);原料磁粉的粒度越大,表面形貌越完整,烧结瓷体的磁导率就越高;替代量在1.20～1.30的范围内,添加2％(质量分数)的Bi2O3可以在900℃低温烧结出磁导率μ'>10,截止频率不低于1GHz的Co-Ti替代钡铁氧体。

Co-Ti substituted barium ferrite powders were prepared by chemical coprecipitation, Effects of Bi2O3 doping and Co-Ti substitution amount on microstructures and high-frequency magnetic properties of low-temperature sintered barium ferrites were investigated with XRD, SEM, TEM and the measurements of complex permeability dispersions. The initial permeability can be promoted with Bi2O3 doping effectively. The proper amount of Bi2O3 doping was Zwt/'o when the diameter of magnetic particles was about 200nm. Larger diameter and more perfect surface morphology would result in higher permeabilities. Barium ferrites with initial permeability μ1 >10. cut-off frequency >lGHz were obtained when it was sintered at 900℃ with 2wt% Bi2O3 in the Co-Ti substitution range 1. 20-1. 30.