本實驗一共製作了 Co/Pt、Ni/Pt、Fe/Pt、CuNi/Pt、Co/Pd、Ni/Pd、Fe/Pd 和 CuNi/Pd 8 個系列的樣品，加上 Ni/Cu 樣品做為參考組來研究不同材料異向性 界面磁阻(AIMR)的現象，對每個樣品分別做了磁場在垂直於電流的平面上旋轉 的 磁 阻 量 測 ， 以 及 磁 場 從 平 行 電 流 方 向 (longitudinal) 轉 到 垂 直 膜 面 方 向 (perpendicular)的磁阻量測。所有樣品確實都有如預期地觀察到異向性界面磁阻 (AIMR)的現象，同時也在 Ni/Pt、Ni/Pd 和 CuNi/Pd 這三組樣品中量到了 ρ
P
>ρL
這個和異向性磁阻(AMR)趨勢相反的特殊現象。
我們探討了 Co/Pt、Ni/Pt、Fe/Pt、CuNi/Pt、Co/Pd、Ni/Pd、Fe/Pd 和 CuNi/Pd 多層膜異向性界面磁阻(AIMR)的現象，同時以 Ni/Cu 多層膜當作對照組，證實 異向性界面磁阻(AIMR)的現象確實是與 Pt 和 Pd 這種擁有很強自旋軌道交互作 用(spin-orbit interaction)的材料有關。
所有樣品的異向性界面磁阻變化(ΔR
TP
)大致上都是隨著每層鐵磁層的膜厚 越薄而增加，其中 Pt 系列的樣品在每層磁性層膜厚薄到 1.67nm~2nm 時，磁阻 的變化ΔRTP
開始下降，Pd 系列的樣品則是只看到ΔRTP
隨著每層鐵磁層的膜厚 越薄而增加，只有 Fe/Pd 的樣品在磁性層膜厚薄到 1.25nm 時ΔRTP
開始下降。異向性界面磁阻(AIMR)的成因可能為磁性層與非磁性層的界面有因磁邊際 效應(magnetic proximity effect)所產生的磁矩在垂直膜面的分量被固定住，或者是 自旋霍爾磁阻(spin Hall magnetoresistance)造成，這個議題目前仍在爭議中。從日 本 E. Saitoh 的團隊量測成長於釔鐵石榴石(YIG)的 Pt 薄膜數據看起來，他們在磁 場從 longitudinal 到 perpendicular 方向上的磁阻量測並沒看到異向性磁阻(AMR) 的現象，而自旋霍爾磁阻(spin Hall magnetoresistance)正好解釋了這個現象，因為 當磁場在 longitudinal 和 perpendicular 方向時，磁矩與電流所產生的所產生自旋 流(spin current)的自旋方向都是垂直的，不應該看到磁阻的變化，所以他們認為 這個磁阻的變化並不是因為 Pt 中的磁性所造成；可是美國 Johns Hopkins 大學錢
80
嘉陵教授的團隊以 x 光磁圓偏振二向性(XMCD)的方法，在成長於 YIG 上 1.5 nm 的 Pt 薄膜量測到 Pt 的磁矩，證明 Pt 在 YIG 上確實會藉由磁邊際效應(magnetic proximity effect)誘發出磁性。
由本實驗多層膜的異向性界面磁阻變化百分比(ΔR
TP
/RP
)隨著每層非鐵磁層 (Pt、Pd)膜厚改變的數據來看，ΔRTP
/RP
會隨著非鐵磁層(Pt、Pd)的膜厚變薄而增 加。若以自旋霍爾磁阻(spin Hall magnetoresistance)的觀點來解釋，非鐵磁層(Pt、Pd)變薄會使自旋流(spin current)變弱，應該導致 ΔR
TP
/RP
隨著非鐵磁層(Pt、Pd) 的膜厚變薄而下降，可是本實驗的ΔRTP
卻隨著非鐵磁層(Pt、Pd)的膜厚變薄而增 加，與錢嘉陵老師團隊所量測的 Pt 中磁阻變化大小隨著 Pt 膜厚變化的趨勢相同，所以自旋霍爾磁阻(spin Hall magnetoresistance)並無法解釋這個現象。
至於為何 Ni/Pt、Ni/Pd 和 CuNi/Pd 的多層膜中磁場垂直膜面的電阻(ρ
P
)會大 於磁場平行電流的電阻(ρL
)，甚至出現了類似異向能中單軸異向性(uniaxial anisotropy)與雙軸異向性(bi-axial anisotropy)耦合的現象，還是無法解釋。81
附錄
82
Resista nce (Ohm)
θ, φ (deg.)
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θ, φ (deg.)
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N=80 N=60
N=40
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θ, φ (deg.)
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θ, φ (deg.)
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(Pt/Co)
xN
/Pt 5T 10KN=20
N=16 N=12
N=8
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θ, φ (deg.)
TP-angle LP-anple
N=4
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θ, φ (deg.)
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(Pt/Co)
xN
/Pt 5T 300KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4 N=8
N=16 N=12
N=20 N=40
N=60 N=80
Co/Pt 多層膜在 300 K 的磁阻量測原始數據
83
Resista nce (Ohm)
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θ, φ (deg.)
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(Pt/Ni)
xN
/Pt 5T 10KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40
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θ, φ (deg.)
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θ, φ (deg.)
TP-angle LP-anple
(Pt/Ni)
xN
/Pt 5T 300KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40 N=16 N=8
Ni/Pt 多層膜在 300 K 的磁阻量測原始數據
84
Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40 N=16 N=8
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θ, φ (deg.)
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θ, φ (deg.)
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Fe/Pt 多層膜在 10 K 的磁阻量測原始數據
Resista nce (Ohm)
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θ, φ (deg.)
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θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
(Pt/Fe)
xN
/Pt 5T 300KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40 N=16 N=8
Fe/Pt 多層膜在 300 K 的磁阻量測原始數據
85
Re si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
(Pt/CuNi)
xN
/Pt 5T 10KRe si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40 N=16 N=8
Re si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
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θ, φ (deg.)
TP-angle LP-anple
Re si sta n ce ( O h m)
θ, φ (deg.)
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Re si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
Re si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
Re si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
CuNi/Pt 多層膜在 10 K 的磁阻量測原始數據
Re si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
Re si sta n ce ( O h m)
θ, φ (deg.)
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Re si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
Re si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
Re si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
Re si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
Re si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
(Pt/CuNi)
xN
/Pt 5T 300KRe si sta n ce ( O h m)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40 N=16 N=8
CuNi/Pt 多層膜在 300 K 的磁阻量測原始數據
86
Resista nce (Ohm)
θ, φ (deg.)
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θ, φ (deg.)
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θ, φ (deg.)
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θ, φ (deg.)
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θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
(Pd/Co)
xN
/Pd 5T 10KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40
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θ, φ (deg.)
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θ, φ (deg.)
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θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
(Pd/Co)
xN
/Pd 5T 300KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40 N=16 N=8
Co/Pd 多層膜在 300 K 的磁阻量測原始數據
87
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θ, φ (deg.)
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θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
(Pd/Ni)
xN
/Pd 5T 10KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40
Resista nce (Ohm)
θ, φ (deg.)
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θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
(Pd/Ni)
xN
/Pd 5T 300KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40 N=16 N=8
Ni/Pd 多層膜在 300 K 的磁阻量測原始數據
88
Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
(Pd/Fe)
xN
/Pd 5T 10KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40 N=16 N=8
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θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
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θ, φ (deg.)
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Fe/Pd 多層膜在 10 K 的磁阻量測原始數據
Resista nce (Ohm)
θ, φ (deg.)
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θ, φ (deg.)
TP-angle LP-anple
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θ, φ (deg.)
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θ, φ (deg.)
TP-angle LP-anple
Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
(Pd/Fe)
xN
/Pd 5T 300KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40 N=16 N=8
Fe/Pd 多層膜在 300 K 的磁阻量測原始數據
89
Resista nce (Ohm)
θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
Resista nce (Ohm)
θ, φ (deg.)
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(Pd/CuNi)
xN
/Pd 5T 10KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40
Resista nce (Ohm)
θ, φ (deg.)
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θ, φ (deg.)
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θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40 N=16 N=8
Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
(Pd/CuNi)
xN
/Pd 5T 300KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
CuNi/Pd 多層膜在 300 K 的磁阻量測原始數據
90
Resista nce (Ohm)
θ, φ (deg.)
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θ, φ (deg.)
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θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
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θ, φ (deg.)
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θ, φ (deg.)
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Resista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
(Cu/Ni)
xN
/Cu 5T 10KResista nce (Ohm)
θ, φ (deg.)
TP-angle LP-anple
N=4
N=12
N=20
N=60 N=80
N=40
Resista nce (Ohm)
θ, φ (deg.)
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θ, φ (deg.)
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θ, φ (deg.)
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(Cu/Ni)
xN
/Cu 5T 300KResista nce (Ohm)
θ, φ (deg.)
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N=4
N=12
N=20
N=60 N=80
N=40 N=16 N=8
Ni/Cu 多層膜在 300 K 的磁阻量測原始數據
91
為了確認 Ni/Pt 和 Ni/Pd 的樣品中ρ
P
>ρL
和類似雙軸異向性特殊現象是在飽 和場底下所量測的結果，所以又在 9 T 下重複量了一次，結果與 5 T 下的量測結 果的相同，結果如下圖。-100 -50 0 50 100 150 200 250 300 350 7.576
7.577 7.578 7.579 7.580
-100 -50 0 50 100 150 200 250 300 350 10.239
10.240 10.241 10.242 10.243
-100 -50 0 50 100 150 200 250 300 350 4.37
4.38 4.39 4.40 4.41
-100 -50 0 50 100 150 200 250 300 350 4.85
4.86 4.87 4.88 4.89 4.90
(Pt/Ni)
xN/Pt 10K N=40
R e si st a n ce (O h m)
θ (deg.)
5T 9T
(Pt/Ni)
xN/Pt 10K N=80
R e si st a n ce (O h m)
θ (deg.)
5T 9T
R e si st a n ce (O h m)
θ (deg.)
5T 9T
(Pd/Ni)
xN/Pd 10K N=60 (Pd/Ni)
xN/Pd 10K N=80
R e si st a n ce (O h m)
θ (deg.)
5T 9T
Ni/Pt 和 Ni/Pd 5 T 與 9 T 量測比較圖
92 參考文獻
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