TiO_2掺杂对高频MnZn功率铁氧体显微结构及磁性能的影响

采用氧化物陶瓷工艺制备2~4MHz高频开关电源用Mn Zn功率铁氧体,通过对铁氧体断面显微结构、密度和磁性能的测试,研究了TiO_2掺杂量对材料微观结构、磁导率和功率损耗的影响。结果表明,随着TiO_2掺杂量的增加,样品平均晶粒尺寸先减小后增大,磁导率单调减小,不同温度(25℃、100℃)下的磁心总功率损耗(激励条件3MHz,10m T、25m T)先减小后增大。说明TiO_2的适量掺杂可以改善高频Mn Zn功率铁氧体的微观结构,降低其功耗。

Effects of TiO2 doping on the microstructure and magnetic properties of high frequency MnZn power ferrites

MnZn power ferrites for 2-4MHz high frequency switch power supply were prepared by conventional oxide ceramic process. The influence of TiO2 doping on the microstructure, permeability and core loss of MnZn power ferrites was investigated by means of characterizing the fracture surface micrograph, density and magnetic properties. The results indicate that with increasing TiO2 doping content the average grain size decreases first and then increases, and permeability decreases monotonously, while the core loss of MnZn power ferrites decreases first and increases subsequently at 25℃ and 100℃ and different exciting condition(3MHz, 10mT and 3MHz, 25mT).The appropriate amount of TiO2 doping can improve the microstructure of MnZn power ferrites and resultantly decrease the core loss of MnZn power ferrites.