利用脈衝式電鍍法合成鈷鎳錳磷與氧化鋁奈米複合硬磁 與相關特性改善之研究

Abstract

在本論文中，成功地將鈷鎳錳磷磁性奈米柱合成在具奈米孔洞的陽極氧化鋁膜中，形成奈米複合磁鐵薄膜；利用脈衝式電鍍法製成直徑為200 ±15奈米、不同高寬比的鎳錳磷磁性奈米柱。相較於直流電鍍法，脈衝式電鍍法可減少永久性磁性奈米柱的缺陷，提升材料分布之均勻性，進而改善微結構下之磁性奈米柱之磁特性。因此，矯頑力2472.3 Oe、最大磁能積16.13 kJ/m3和方正性0.59得以被實現。此外，我們已成功地堆疊、黏合並磁化15層的鈷鎳錳磷磁性奈米柱-陽極氧化鋁之複合薄膜，堆疊後之總體積為9mm3；此堆疊複合磁性薄膜之最大表面磁場為4.99mT，和市售尺寸3.14mm3的釤鈷圓柱磁鐵之最大表面磁場相比，堆疊複合磁性薄膜已達其值之30%。該結果顯示了未來在MEMS應用上，利用與CMOS相容之製程所製成的微型磁鐵的潛力。

In this thesis, CoNiMnP magnetic nanowires have been successfully synthesized with different aspect ratios in the AAO membrane, which is 200±15nm in diameter to form a nanocomposite magnet using pulse electrodeposition method. Comparing with the direct current plating method, such a technique can provide better material characteristics in terms of less defect and good homogeneity in the microstructure of the magnetic nanowires. Accordingly, the coercivity of 2472.30Oe, maximum energy density product, BHmax, of 16.13 kJ/m3, and squareness up to 0.59 can be achieved. In addition, we have successfully stacked, bonded, and magnetized 15 layers of CoNiMnP-AAO nanocomposite with the size of 9 mm3, the highest surface magnetic field strength can be as high as 4.99mT, which is almost 30% of the field strength from the one made of commercial SmCo cylinder hard magnet with the size of 3.14mm3. The results have shown the potential development of the micromagnets, which can be fabricated using CMOS compatible process for future MEMS applications.