宽频高阻抗贫铁MnZn铁氧体的掺杂改性研究

Study on doping modification of Fe-poor MnZn ferrites with high impedance at wide-band

采用传统陶瓷工艺制备了MnZn和NiZn铁氧体材料。研究了贫铁MnZn铁氧体、富铁MnZn铁氧体及NiZn铁氧体的电阻率和阻抗的频率特性。结果表明:CaCO3-SiO2联合掺杂能大幅度提高贫铁MnZn铁氧体材料的电阻率,在最大添加量w(SiO2)为0.005%,w(CaCO3)为0.04%时,有最大电阻率10246Ω·m;贫铁MnZn铁氧体材料综合了富铁MnZn铁氧体材料的低频高阻抗和NiZn铁氧体材料的高频高阻抗特性;Fe2O3、TiO2含量的增加都会提高材料的低频阻抗,降低材料的高频阻抗。

MnZn ferrites and NiZn ferrites were dependence of resistivity and impedance of ferrite prepared by conventional ceramic processing techniques. The frequency samples were studied. The resistivity of MnZn ferrites with Fe-poor composition （less than 50% of Fe2O3） increases with CaCO3-SiO2 addition rapidly. The maximum resistivity is 10 246 Ω·m when w（SiO2）= 0.005% and w（CaCO3）= 0.04%. The impedance of Fe-poor MnZn ferrites compares with that of Fe-rich ferrites in low frequency region, and it is still high enough to compare with that of NiZn ferrites in high frequency region. The impedance of Fe-poor MnZn ferrites at low frequency increases with contents of Fe2O3 and TiO2 increasing, and the high frequency impedance decreases with the contents of Fe2O3 and TiO2 increasing.