奈米結構對YBCO臨界電流密度影響

The Influence of Nano-structure on YBCO Critical Current Density

曾為隆(Wei-Lung Tzeng)

指導教授 ： 王耀德

國立臺北科技大學/電資學院/光電工程系研究所/碩士(2009年)

摘要

本實驗利用超音波噴霧技術，在鈮酸鋰(LiNbO3)基板上成長YBCO薄膜。第一階段先將硝酸釔、硝酸鋇、硝酸銅溶解於去離子水中，再用超音波噴霧系統將先驅物沉積在基板上。沉積後之樣品放入高溫爐反應，改變反應時間、溫度及反應氣體成長YBCO薄膜，接著再利用XRD、四點探針分析結構與電性，找出最佳實驗參數。第二階段將奈米金溶液混入硝酸溶液中，參照最佳實驗參數，製作出以奈米金粒子為人造缺陷的超導薄膜。
實驗發現最佳反應時間為10分鐘，不同反應氣體將影響超導薄膜的晶相。在人造缺陷方面，由於混入奈米金粒子，使得臨界電流密度上，在混入溶液體積比為8:2時，由5000 A/cm2上升至7500A/cm2。

關鍵字

超音波噴霧 ； 超導薄膜 ； 奈米金粒子 ； 扎釘力

並列摘要

In this thesis, YBCO thin films were deposited on LiNbO3 by using ultrasonic spray technique. First, nitrate solution which includes yttrium nitrate, barium nitrate and copper nitrate was dissolved in DI water. Then, ultrasonic spray system was employed to deposit precursor on the substrates. Finally, the as-deposited samples were reacted in furnace. The different experiment parameters, reacting time and reacting ambient atmosphere, were optimized by four-probe measurements and XRD results.

The nano-Au particles were mixed in YBCO precursor for artificial defects. The nano-gold particles were added into the nitrate solution. Then, sprayed the precursor on substrates and reacted in furnace. Finally we investigated the R-T, Jc and structure by four-probe measurement and XRD.

The reacting atmosphere affects the YBCO crystalline structure. The 10mins reacting time in argon had the best result of XRD, R-T and SEM. The results of XRD showed the nano-Au particles which mixed with YBCO thin film. When the volume ratio of nano-Au solution to precursor solution was 8:2, there showed the best Jc, 7500A/cm2.

並列關鍵字

ultrasonic spray ； superconducting thin film ； nano-Au particles ； pinning force

參考文獻

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