本研究係探討二價錳離子的添加對於M相鈣鐵氧磁體燒結後顯微結構及電性的影響，使用SEM 觀察M相鈣鐵氧磁體的顯微結構，元素分析在晶界的部分發現第二相的存在，分析後得出其為反應的中間相析出，而晶界與晶粒之間存在不同的La及Mn元素比例將可能導致影響電性。
以四點探針分析不同錳比例試片之直流電阻率，分析其導電機制，並算出其導電活化能，發現隨著錳離子的添加量增加，導電活化能電阻率隨之上升。
將不同錳比例的試片，利用交流阻抗分析得出其RC元件電阻值，得出Mn 0.2~0.4皆存在兩種電阻，由元素分布的分析推論為可能為晶界與晶粒電阻，將其對溫度做圖後，分析其導電活化能，與塊材導電活化能比較，得出直流電阻率主要由晶界電阻控制。

The point of this paper is the effects of Mn2+ doping on micro-structures and conduction behavior of M-type calcium ferrite. Second phase was Found in grain boundaries of M-type Calcium ferrite with SEM and EDS analysis. The precipitated second phase is the mesosphere of reaction. The atomic ratio of La and Mn in grain and grain boundary are different, the different may influence the Electrical Properties of M-type calcium ferrite.
Using four probe method to measure the DC electrical resistivity of different Mn ratio, and analysis the conduction mechanism. The result discover that with Mn doping amount increase, the resistivity and conducting activation energy increase.
Using AC impedance measurement to analysis different Mn amount, get its RC element resistance, the result is that in Mn amount 0.2~0.4 all have two different resistance. With EDS analysis the different resistance might be grain and grain boundary resistance. Plot graphs of resistance against temperature, and analysis the conducting activation energy, compare to DC conducting activation energy, conclude that the DC resistivity is controlled by grain boundary.

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