BaO掺杂对高频MnZn功率铁氧体性能的影响

Influences of Ba O addition on the properties of high frequency Mn Zn power ferrites

采用氧化物陶瓷工艺制备Mn Zn铁氧体,研究了Ba O掺杂量对高频Mn Zn功率铁氧体微观结构和磁性能的影响。结果表明,少量的Ba O掺杂可以使铁氧体烧结样品的晶粒尺寸增大,密度和饱和磁感应强度提高,功耗降低,而过量加入后会出现过烧现象,功耗增加,饱和磁通密度和密度有所下降。烧结样品的起始磁导率随Ba O掺杂量的增加单调下降。在1260℃烧结温度下,当Ba O掺杂量为0.025wt%时,样品具有最低功耗值,且其他磁性能也较好。另外,与不掺杂Ba O的最佳烧结条件下铁氧体样品相比,1260℃烧结掺杂量为0.025wt%的材料起始磁导率降低,但功耗的温度特性更优。

Mn Zn ferrites with composition of Mn0.73Zn0.18Fe2.09O4 were prepared by conventional oxide ceramic process. Influences of Ba O addition on their microstructure and magnetic properties were investigated. The SEM pictures reveal that a proper amount of Ba O addition results in increase in grain size and saturation magnetic flux density, and decrease in power losses. However, doping excessive Ba O（0.025wt%） leads to oversintering phenomenon which makes power losses increase, and meanwhile, density and saturation magnetic flux density decrease slightly. The initial permeability descends monotonously with increasing Ba O addition. Sample with Ba O addition of 0.025wt% and sintered at 1260℃ has minimum power loss, and better magnetic properties. Besides, compared with the Ba O-free sample sintered under best condition, the initial permeability of sample with Ba O addition of 0.025wt% and sintered at 1260℃ decreases, but its power loss exhbits a better temperature dependence.