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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/79498


    Title: 增強鎳(Ni)參雜錫(Sn)奈米粒子的超導性;Enhanced superconductivity in Ni-doped Sn nanoparticles
    Authors: 古亦娜;Gultom, Vina Agustina
    Contributors: 物理學系
    Keywords: SnO2;納米粒子;X 射線衍射;超導性;SnO2;nanoparticles;x-ray diffraction;superconductivity
    Date: 2019-01-25
    Issue Date: 2019-04-02 14:33:08 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 本研究探討了Sn 和Ni 納米顆粒(NPs)複合體系的超導(SC)現象。 我們分
    析了Sn 摻雜Ni 的合成壓力對四方相形成的影響。 通過熱蒸發方法製造Sn 和Ni 納米
    顆粒,使用兩個分離的蒸發源進行單獨蒸發; 並且藉由各種惰性氣體的壓力的控制顆粒
    的尺寸。 對於Sn 側,加熱電流為~50A,對於Ni 側,加熱電流為~80A,相應的氬氣壓
    力為0.18 托和0.08 托。 使用X 射線繞射法進行晶體結構的表徵分析,然後與Rietveld
    精製結合以確定樣品組成和微晶尺寸。 對於第1,第2 和第3 樣品的微晶尺寸分別達到
    34.6(9)nm,33.8(9)nm 和30.1(2)。
    在1.8K 和未施加磁場下測量這些樣品的AC 磁化率,從而出現超導狀態。使用
    Scalapino 配件測試每個樣品。 Scalapino 擬合是通過關聯磁化率和溫度來確定超導參數
    的良好描述。此外,當施加磁場Ha = 0 Oe 時,隨著樣品的粒徑減小,電子間隙δ 也變
    大,穿透深度變大,0.192(8)nm,δ= 0.00206(4)kBTC,0.26 (1)nm 與δ= 0.01
    (7)kBTC,1.1(2)nm,δ= 0.08(4)kBTC,表明施加的磁場將完全穿透納米粒子,
    並導致抗磁效應被完全破壞。當樣品的微晶尺寸變小時,臨界磁場增加,這意味著抗
    磁效率越來越好。令人驚訝的是,30.1(2)nm 的臨界溫度比塊體的臨界溫度高108 倍
    (可接受的錫邊界溫度實驗值為3.722K)。此特殊樣品具有SnO2 結構,因此提升了臨
    界溫度。;Herein, this study reports the superconductivity (SC) phenomena of Sn and Ni
    nanoparticles (NPs) composite systems. We analyzed the influence of the synthesis pressure
    of Sn-doped Ni in the formation of the tetragonal phase. Sn and Ni nanoparticles have been
    fabricated by the thermal evaporation method with two decoupled evaporation sources for
    separate evaporation; and the size of particles with various inert gas pressures was controlled.
    The heating current is ~50 A for Sn side and ~80 A for Ni side with the respective argon
    pressure of 0.18 torr and 0.08 torr. The characterization of crystal structure was performed using
    experimental techniques such as X-ray diffraction method, then allied with Rietveld refinement
    to determine the sample composition and crystallite size. The crystallite size of these samples
    were achieved 34.6(9) nm, 33.8(9) nm and 30.1(2), respectively for the sample 1, sample 2 and
    sample 3.
    The AC susceptibility of these samples was measured at 1.8 K and zero applied
    magnetic field, thus the superconducting state appeared. Each sample was tested using the
    Scalapino fitting. Scalapino fitting is a good description to determine the superconducting
    parameters by relating the magnetic susceptibility and temperature. In addition, when applied
    magnetic field Ha = 0 Oe, the penetration depth becomes larger as the particle size of the sample
    decreases and the electron gap δ become larger as well, 0.192(8) nm with δ = 0.00206(4) kBTC,
    0.26(1) nm with δ = 0.01(7) kBTC, 1.1(2) nm with δ = 0.08(4) kBTC, respectively, indicating
    that the applied magnetic field will completely penetrate the nanoparticles, and causing the
    diamagnetic effect to be completely destroyed. Surprisingly, the critical temperature of 30.1(2)
    nm is achieve higher 108 times than that of the bulk (the accepted experimental value of the tin
    boundary temperature is 3.722K) kOe. This interesting sample has SnO2 structure and it made
    an enhancement on the critical temperature.
    Appears in Collections:[Graduate Institute of Physics] Electronic Thesis & Dissertation

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