化学共沉淀工艺及焙烧温度对钡铁氧体纳米粉末性能的影响

Effect of chemical co-precipitation process and calcination temperature on the properties of barium ferrite nano-powders

通过化学共沉淀和后续焙烧工艺制得了纳米级六角(M)型钡铁氧体(BaFe12O19)颗粒。分析表明,BaFe12O19颗粒的品质与化学共沉淀反应时长以及焙烧温度的高低密切相关:随着化学共沉淀反应时间的延长,其反应产物经焙烧后制得的BaFe12O19相体积分数愈高;化学共沉淀反应时间相同时,焙烧温度愈高,产物粒径愈大;焙烧温度相同时,化学共沉淀反应时间愈长,产物粒径愈大。当化学共沉淀反应时间为5h、焙烧温度为900℃时,得到磁性能最佳的硬磁颗粒:矫顽力Hc=5934 Oe,剩磁温度系数(α)=–0.176%/℃,矫顽力温度系数(β)=0.043%/℃;当化学共沉淀反应时间为5h、焙烧温度为1100℃时,测得焙烧产物的饱和磁化强度Ms为66.9emu/g,已接近BaFe12O19的饱和磁化强度理论值(72.0 emu/g)。

Hard magnetic barium hexaferrite(BaFe12O19)nanoparticles have been synthesized via a co-precipitation and calcination process.Prolonged co-precipitation reaction time improved the crystallization of BaFe12O19.The particle size increased with increasing calcination temperature while co-precipitation reaction time is the same.Meanwhile,the particle size also increased with prolonging co-precipitation reaction time while calcination temperature is the same.The products with Hc of 5934 Oe,temperature coefficient of remanence(α)of–0.176%/℃and temperature coefficient of coercivity(β)of 0.0427%/℃were obtained when co-precipitated for 5 h and calcined at 900℃.The nanoparticles co-precipitated for 5 h and calcined at 1100℃has a saturation magnetization of 66.9 emu/g,approaching the theoretical saturation magnetization.