Fe_2O_3含量对MnZn铁氧体中Fe~(2+)量、磁性能及导电机制的影响

通过测量MnZn铁氧体的磁性能及Fe2+、Mn3+含量,考察了MnZn铁氧体中的Fe2+含量与配方中Fe2O3、MnO含量的关系及其对MnZn铁氧体磁性能的影响,并探究了MnZn铁氧体的导电机制。结果表明:随着(Fe2O3)a(MnO)b(ZnO)c主组成配方中a值递增(52.55≤a≤53.35)、b值递减(38.33≥b≥37.52),呈现出Fe2+、Mn3+含量均增加的趋势。随着Fe2+含量增加,Pcv谷底温度向低温方向移动,Pcv(min)先减后增,Pcv(20/70/100℃)均先减后增,均在Fe2+含量=1.55%附近达到最小值;起始磁导率μi(20/70/100℃)均先增后减。根据Pcv-Fe2+含量和μi-Fe2+含量两个关系图在Fe2O3=53.15mol%附近出现极值点这一现象,初步推测铁氧体Znα2+Mnβ-x2+Mnx3+Fey2+Feχ-y3+O4+σ(0.1794≥α≥0.1786,0.754≥β≥0.734,0.0031≤x≤0.0040,0.051≤y≤0.070)的导电机制为:y0.064时小极化子间的束缚能主导,y0.064时电子跃迁主导。

Effects of Fe2O3 content on the Fe2+concentrations,magnetic properties and conductive mechanism of MnZn ferrites

Magnetic properties of MnZn ferrites were measured together with the Fe2+and Mn3+concentrations for MnZn ferrite samples with the formula of (Fe2O3)a(MnO)b(ZnO)c (52.55≤a≤53.35, 38.33≥b≥37.52). We investigated the relationship between content of Fe2O3, MnO and Fe2+ concentration of MnZn ferrites, and analyzed the conductive mechanism of MnZn ferrites. The result indicates that both Fe2+ and Mn3+ contents increase with increasing a and decreasing b. With the increase of Fe2+concentration, both Pcv(min) and Pcv(20,70,100℃) decrease first and then increase over the Fe2+concentration of about 1.55%, butμi changes in the opposite way. For the conductive mechanism of a MnZn ferrite formulated Znα2+Mnβ-x2+Mnx3+Fey2+Feχ-y3+O4+σ(0.1794≥α≥0.1786,0.754≥β≥0.734,0.0031≤x≤0.0040,0.051≤y≤0.070), the influence of polaron binding energy is expected to be important at y<0.064, while electron jump is dominant when y>0.064.