纳米SiO_2添加量对Mn-Zn铁氧体显微结构及功耗的影响

Effect of the Amount of Doped Nano-SiO_2 on the Microstructure and Power Loss of Mn-Zn Ferrites

对添加纳米级SiO2和普通级CaCO3组合对Mn-Zn铁氧体功率损耗的影响进行研究,采用扫描电子显微镜对Mn-Zn铁氧体材料的显微结构、晶界以及元素分布进行观察分析。结果表明,适量的纳米SiO2(与CaCO3组合)掺杂能够改善烧结铁氧体的微观结构并显著降低功率损耗,纳米SiO2添加量应不大于0.005%(wt),并发现在不同的测试温度下,SiO2添加量有不同的最佳值。在较低温度(≤60℃)下,纳米SiO2的最佳添加量为0.0025%(wt)。当材料在较高温度(≥80℃)测试时,适宜的纳米SiO2添加量为0.005%(wt)。

The effect of doped nano-SiO2 and CaCO3 on the power loss of Mn- Zn ferrites was investigated,and scanning electron microscopy was used to analyze the microstructure, grain boundary and elements distribution of Mn - Zn ferrites. The results showed that the suitable doped nano-SiO2 with CaCO3 together was able to improve the microstiucture of sintered ferrites and reduce the power loss obviously. The amount of doped nano-SiO2 should not be greater than 0. 005 % （wt）, most of the doped Ca and Si were distributed along the grain boundary. Under different test temperature, the optimum content of nano-SiO2 had a different value, the suitable content of nano-SiO2 dopants is about 0.0025%（wt） with the test temperature below 60 ℃, while that will be raised up to 0. 005 % （wt） when the test temperature is above 80 ℃.