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研究生: 李釗豪
Lee, Jhao-Hao
論文名稱: 鐵磁/一般金屬異質結構的鐵磁共振與自旋電子學之研究
Study of Ferromagnetic Resonance and Spintronics in FM/Normal Metal Heterostructures
指導教授: 江佩勳
Jiang, Pei-hsun
學位類別: 碩士
Master
系所名稱: 物理學系
Department of Physics
論文出版年: 2016
畢業學年度: 104
語文別: 中文
論文頁數: 39
中文關鍵詞: 自旋電子學鐵磁共振自旋幫補效應自旋霍爾效應
英文關鍵詞: Spintronics, Ferromagnetic Resonance, Spin Hall Effect, Spin Pumping Effect
DOI URL: https://doi.org/10.6345/NTNU202203618
論文種類: 學術論文
相關次數: 點閱:121下載:27
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  • 我們使用E-beam lithography和Photo lithography技術將樣品製作成狹長型的結構並且使用Microstrip以及共平面波導(coplanar waveguide,CPW)來輸入微波訊號,目前我們實驗成功的量測到鐵磁共振(ferromagnetic resonanceand,FMR)訊號。

    當鐵磁材料/一般金屬異質結構在鐵磁共振的條件下,因為自旋幫補效應(spin pumping effect,SPE),使得自旋流不斷地流入一般金屬。我們利用鐵磁共振的訊號分析磁化飽和量 以及Gilbert阻尼參數 ,比較單層鐵磁材料以及鐵磁/一般金屬異質結構材料的 ,發現鐵磁/一般金屬異質結構的 大於單層鐵磁材料的 ,得知我們使用鐵磁/一般金屬異質結構(Py/Pt)有自旋流成功的產生。

    然而自旋電流無法直接地被量測到,但是因為自旋-軌道作用(spin–orbit interaction)導致逆自旋霍爾效應(inverse spin Hall effect,ISHE)進而產生電荷電流,未來我們會在樣品的兩端再加上直流(DC)訊號的量測。在此實驗中除了ISHE還會有自旋整流效應(spin rectification effect,SRE)為了區分這兩種不同訊號的電流,未來我們將會使用了此篇論文[1]的方法來進行室溫實驗的分析,並且使用[2]的方法在低溫環境(< 1.5K)下做測量分析。

    We use E-beam lithography and Photo lithography to make slim FM/Normal metal heterostructures.Microwave signal entered by microstrip or coplanar waveguide (CPW)and we success measure ferromagnetic resonanceand (FMR) signal.

    When FM/Normal metal heterostructures occur ferromagnetic resonanceand,the spin current continuously flow to normal metal because of spin pumping effect (SPE).Then we use FMR signal to analysis saturated magnetization and Gilbert damp parameter . Compare single ferromagnetic layer and FM/Normal metal heterostructures,we find Gilbert damp parameter of heterostructures larger than of single ferromagnetic layer.This result make we know that spin current was produced in FM/Normal metal heterostructures.

    However , spin current can’t measure directly. But we can measure charge current that resulting in inverse spin Hall effect (ISHE) caused by spin–orbit interaction (SOC). In the future, Our experiment will add DC pad in order to detecting DC signal. Then we will measure ISHE and spin rectification effect (SRE) signal. In order to distinguishing ISEH and SRE signal, we will use this method [1] in room temperature and this method [2] in low temperature (< 1.5K).

    摘要 i Abstract ii 致謝 iii 目錄 iv 1 理論回顧 1 1.1 鐵磁共振 1 1.1.1 拉莫爾進動(Lamor precession) 1 1.1.2 均勻磁場下的鐵磁共振 2 1.1.3 Landau–Lifshitz–Gilbert equation 4 1.2 自旋電子學 6 1.2.1 自旋霍爾效應(spin hall effect,SHE) 6 1.2.2 自旋幫浦效應(spin pumping effect,SPE) 6 1.2.3 自旋整流效應(spin rectification effect,SRE) 7 2 儀器介紹和實驗方法 10 2.1 掃描式電子顯微鏡 11 2.2 電子束蒸鍍儀 13 2.3 向量網路分析儀 14 2.4 共平面波導(co-planar waveguide,CPW) 17 2.5 樣品製程 20 2.5.1 旋轉塗佈(Spin coated)&預烤 20 2.5.2 曝光 20 2.5.3 顯影 21 2.5.4 蒸鍍 21 2.5.5 舉離(lift-off) 21 2.5.6 鍍上樣品 22 2.6 實驗方法 23 2.6.1 推測材料在FMR實驗時的外加磁場和共振頻率 24 2.6.2 量測FMR訊號並且找出共振磁場Hr 25 2.6.3 找出半高寬 25 2.6.4 找出樣品磁飽和量 以及Gilbert阻尼參數 26 2.6.5 未來展望:分析直流(DC)訊號 26 3 結果與討論 28 3.1 Microstrip測量樣品Py 15 nm 28 3.2 Microstrip測量樣品Py 15 nm / Pt 15 nm 29 3.3 CPW測量樣品Py 15 nm 30 3.4 CPW測量樣品Py 30 nm 31 3.5 磁飽和量 以及Gilbert阻尼參數 32 4 總結 36 5 參考文獻 38

    1. Bai, L.H., et al., Distinguishing spin pumping from spin rectification in a Pt/Py bilayer through angle dependent line shape analysis. Applied Physics Letters, 2013. 102(24): p. 242402.
    2. Bai, L., et al., Universal Method for Separating Spin Pumping from Spin Rectification Voltage of Ferromagnetic Resonance. Physical Review Letters, 2013. 111(21): p. 217602.
    3. GRIFFITHS, J.H.E., Anomalous High-frequency Resistance of Ferromagnetic Metals. Nature, 1946. 158: p. 670-671.
    4. Kittel, C., Interpretation of Anomalous Larmor Frequencies in Ferromagnetic Resonance Experiment. Phys. Rev., 1947. 71: p. 270.
    5. Vonsovskiĭ, S.V., Ferromagnetic resonance; the phenomenon of resonant absorption of a high-frequency magnetic field in ferromagnetic substances. International series of monographs on solid state physics, ed. 4. 1966, Oxford, New York, Pergamon Press.
    6. Kittel, C., On the Theory of Ferromagnetic Resonance Absorption. Phys. Rev., 1948. 73: p. 155.
    7. Gilbert, T.L., A phenomenological theory of damping in ferromagnetic materials. IEEE Transactions on Magnetics, 2004. 40(6): p. 3443-3449.
    8. Wirthmann, A., et al., Direct phase probing and mapping via spintronic michelson interferometry. Physical review letters, 2010. 105(1): p. 017202.
    9. Sinova, J., et al., Universal Intrinsic Spin Hall Effect. Physical Review Letters, 2004. 92(12): p. 126603.
    10. Tserkovnyak, Y., A. Brataas, and G.E.W. Bauer, Spin pumping and magnetization dynamics in metallic multilayers. Physical Review B, 2002. 66(22): p. 224403.
    11. Gui, Y.S., et al., Realization of a Room-Temperature Spin Dynamo: The Spin Rectification Effect. Physical Review Letters, 2007. 98(10): p. 107602.
    12. Mecking, N., Y.S. Gui, and C.M. Hu, Microwave photovoltage and photoresistance effects in ferromagnetic microstrips. Physical Review B, 2007. 76(22): p. 224430.
    13. Harder, M., et al., Analysis of the line shape of electrically detected ferromagnetic resonance. Physical Review B, 2011. 84(5): p. 054423.
    14. Neto, A.C., et al., The electronic properties of graphene. Reviews of modern physics, 2009. 81(1): p. 109.
    15. Chen, L.F., et al., in Microwave Electronics. 2005, John Wiley & Sons, Ltd.
    16. Chappert, C., et al., Ferromagnetic resonance studies of very thin cobalt films on a gold substrate. Physical Review B, 1986. 34(5): p. 3192-3197.
    17. Gui, Y., L. Bai, and C. Hu, The physics of spin rectification and its application. Science China Physics, Mechanics and Astronomy, 2013. 56(1): p. 124-141.
    18. Mizukami, S., Y. Ando, and T. Miyazaki, Effect of spin diffusion on Gilbert damping for a very thin permalloy layer in Cu/permalloy/Cu/Pt films. Physical Review B, 2002. 66(10): p. 104413.
    19. Tserkovnyak, Y., A. Brataas, and G.E.W. Bauer, Enhanced Gilbert Damping in Thin Ferromagnetic Films. Physical Review Letters, 2002. 88(11): p. 117601.
    20. Magnetic Materials and Their Characteristics, in Transformer and Inductor Design Handbook, Fourth Edition. 2011, CRC Press. p. 1-54.

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