複鐵式材料同時具有鐵電和鐵磁性，在材料中鐵電與鐵磁性彼此會互相作用形成磁電效應。磁電現象主要的價值在於元件應用上多了一維的控制變數，可以經由電、磁、或機械方式予以監控，對元件之設計提供了許多彈性和幫助。
本實驗利用化學共沉法製備鐵酸鉍 (BiFeO3)及鈷鐵氧體粉末(CoFe2O4)。且本實驗在製程上利用傳統的陶瓷混粉方式，除了易於控制成分比例外，也成功製作出皆為純相的鐵酸鉍及鈷鐵氧體複合式塊材。同時也製備出摻雜鑭元素鐵酸鉍粉末及與鈷鐵氧體複合式塊材。探討不同成分比例及摻雜離子對複合式塊材的電性及磁性的影響。
本論文分為三部份來討論，首先是鐵酸鉍、摻雜鑭元素鐵酸鉍及鈷鐵氧體粉末性質作探討。接著是鐵酸鉍及鈷鐵氧體複合式塊材的電性及磁性結果。最後則是摻雜鑭元素鐵酸鉍及與鈷鐵氧體複合式塊材的電性及磁性結果。
由結果得知，BFO/CFO的介電性質除了x=0.1外, 其餘都會有明顯空間電荷造成的現象,使得介電損失跟低頻的介電常數變大的趨勢。磁性方面，x=0.1便可以使原本順磁表現的BFO變成鐵磁性，且飽和磁化量也隨著增加。但在鐵電性質上，會由於漏電流使得曲線不容易判斷是否飽和。
而在BLFO/CFO的系統，雖然BLFO的介電性質表現較好，但是並無法明顯改善BLFO/CFO這個系統的介電性質表現。而在磁性表現上面，也成功使得其複合式塊材擁有鐵磁性，且由於摻雜鑭元素的關係，使得矯頑場有明顯的變動。但在鐵電性質上，也是由於漏電流使得曲線不容易判斷是否飽和。

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