• 沒有找到結果。

6-1 結論

1. 根據 XPS 表面成分與 SIMS 縱深分析,證實薄膜中銅的含量隨著直流濺鍍電流 上升而提高,但受限於檢測深度以及元素特性,薄膜表面(7-8nm)的參雜比例 與預期的參雜比例不一致,但從 XPS 與 SIMS 數據間的吻合,確定檢測誤差對 參雜比例的影響,故使用膜厚計鍍率計算元素參雜比例是一種可行的方法。

2. 從 X 射線繞射圖形顯示,50nm 鈷鐵硼銅薄膜,銅比例為 9 以及 24%時結構為 非結晶態,並非預期地多晶態,由於銅易堆積成面心立方結構,且金屬不易 形成非結晶態,但當銅增加至 66%時 XRD 圖形顯示在 2θ = 43.5° 出現微弱的 Cu(111)訊號。

3. 40nm 薄膜作 AFM 表面形貌影像,顯示表面平均粗糙度為 0.4-1.7nm,表面晶 粒尺寸為 400-1400nm2;銅參雜比例在 15-37%,銅比例提高時,表面粗糙度與 表面晶粒尺寸也隨著上升,當銅比例增加為 44%時,表面粗糙度與表面晶粒尺 寸皆下降。

4. MOKE 數據顯示,磁易軸矯頑場(Hc)隨著 CoFeB 含量增加而上升,50nm 薄膜 CoFeB 含量從 32-100%,Hc 從 13 增加至 105Oe,40nm 薄膜 CoFeB 含量 56-100%,

Hc 從 37 增加至 106Oe;比較 40 與 50nm 的矯頑場大小,推測銅與鈷鐵硼共濺 鍍增加鐵磁性物質間的距離,降低交換耦合作用,故銅參雜愈多矯頑場愈低。

5. 根據矯頑場與表面粗糙度的反比關係,瞭解鈷鐵硼銅薄膜於磁化過程中,磁 區壁翻轉方式為非同調磁區壁旋轉(non-coherence domain wall ratation)。

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6. FMR 數據作數值擬合,得到飽和磁化強度(Ms)隨著銅增加而遞減,50nm 薄膜 Cu 比例從 0-68%,Ms 從 753 降低至 254emu/cm3,40nm 薄膜 Cu 比例從 0-44%,

Ms 從 622 降低至 340emu/cm3,與參考資料具有相同數量級的飽和磁化強度。

7. 阻尼常數(α)隨鈷鐵硼含量作遞減,40nm 鈷鐵硼含量從 56-100%,α的變化從 0.010 至 0.019,50nm 鈷鐵硼含量從 32-100%,α變化從 0.008 至 0.017,阻 尼常數比參考資料還高,推測是參雜銅於鈷鐵硼中,造成鐵磁物質間的進動 方向與頻率的不一致,導致阻尼常數的上升。

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