稀土Dy掺杂SrFe_(12)O_(19)永磁铁氧体的结构与性能

The properties and structure of dysprosium-doped SrFe_(12)O_(19) permanent magnetic ferrite

研究了掺杂稀土Dy对锶铁氧体制备工艺、结构与性能的影响关系。研究表明,取向磁场对铁氧体磁性能的影响十分显著:随着取向磁场强度的增加,锶铁氧体晶粒发生的晶面择优取向度也增大,剩磁Br、最大磁能积(BH)max和矫顽力Hc均有上升趋势。烧结温度的影响则较复杂:随着烧结温度的增加,剩磁Br和最大磁能积(BH)max均有上升趋势,而矫顽力Hc则呈下降之势。通过在Y30牌号SrFe12O19预烧料基础上掺杂0.2%Dy2O3,经700kA/m磁场、4414N/cm2压力湿法成型的样品在1230℃温度下烧结1h后的磁性能达到了Br=398mT、Hcj=254kA/m和(BH)max=29.1kJ/m3,它与不掺杂Dy2O3的样品相比分别提高了12mT、31kA/m和0.7kJ/m3。

Influence of Dy-doping on preparation, structure and magnetic properties of the Sr ferrites has been studied in this paper. It is found that the orientation magnetic field has a marked effect on the magnetic properties of obtained ferrite. Remanenee Br, maximal magnetic energy product （BH）max and coercivity Ho as well as grain preferential-orientation degree of the ferrites increase with a increase of the orientation magnetic field. However, the effect of sintering temperature is more complicate. As the rising of sintering temperature, the remanence Br and （BH）mox of ferrite improve, while the coercivity Ho~ decreases. With the addition of 0.2% DyzO3 to presinterecl SrFe12O19 powder （trademark Y30）, the ferrites prepared processed with wet-pressing at 700kA/m magnetic field, 4414N/cm2 pressure and lh sintering under 1230℃ have a remanence Br of 398mT, a coercivity Hcj of 254kA/m, and a maximum magnetic energy product （BH）max of 29. lkJ/m3 with an increment of 12roT, 31kA/m and 0.7kJ/m3 respectively compared without Dy2O3 addition samples.