本文關(guān)鍵詞： YBCO超導(dǎo)薄膜 射頻磁控濺射 LMO模板層 LMO:MgO復(fù)合薄膜　出處：《電子科技大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：以YBa2Cu3O7-x(YBCO)為典型代表的第二代高溫超導(dǎo)帶材具有成本較低、載流能力高、機(jī)械強(qiáng)度好且可大批量生產(chǎn)等優(yōu)點(diǎn),所以YBCO超導(dǎo)帶材在電能存儲、電力傳輸以及強(qiáng)磁場等領(lǐng)域里面存在著非常廣闊的應(yīng)用。YBCO薄膜的良好生長離不開一個高質(zhì)量的模板層。本論文主要沿用IBAD技術(shù)路線,以LMO薄膜作為模板層。但為了提高YBCO薄膜在磁場下的性能,嘗試采用LMO:MgO復(fù)合薄膜代替LMO薄膜作為新的模板層。從生長工藝參數(shù)等入手,分別對LMO薄膜和LMO:MgO復(fù)合薄膜的生長進(jìn)行了系統(tǒng)的研究。本論文的具體研究內(nèi)容包括以下幾個方面:1、射頻磁控濺射LMO薄膜的生長條件研究:通過調(diào)節(jié)沉積溫度、濺射功率、Ar氣壓等工藝條件,對LMO模板層的生長窗口進(jìn)行研究。在最優(yōu)化的工藝條件下,制得的LMO模板層薄膜(002)取向面外半高寬為3?,(110)面面內(nèi)半高寬為5.4?,表面粗糙度為2 nm,為YBCO超導(dǎo)層提供了高質(zhì)量的模板層。在研究過程中,還對LMO薄膜的生長機(jī)制進(jìn)行了一定的分析。2、LMO薄膜的表面粗糙度對YBCO超導(dǎo)薄膜結(jié)構(gòu)和性能的影響研究:主要研究了YBCO薄膜的結(jié)構(gòu)和性能隨著LMO薄膜表面粗糙度的變化情況。最后研究結(jié)果表明:隨著LMO薄膜表面粗糙度從7 nm降到1.3 nm,YBCO薄膜的結(jié)構(gòu)得到改善,臨界電流密度也從1 MA/cm2上升到2.4 MA/cm2。3、射頻磁控濺射LMO:MgO復(fù)合薄膜的生長研究:以LMO薄膜的工藝條件作為參考,進(jìn)一步優(yōu)化了LMO:MgO復(fù)合薄膜的生長窗口,并對LMO:MgO復(fù)合薄膜生長的情況進(jìn)行了討論。分別在單晶LAO基底和長有IBAD MgO薄膜的哈氏合金基帶上生長LMO:MgO復(fù)合薄膜。最后得到了LMO與MgO兩相大致分離生長的LMO:MgO復(fù)合薄膜。4、在LMO:MgO復(fù)合薄膜上生長YBCO超導(dǎo)薄膜。比較了兩種薄膜上生長的YBCO薄膜結(jié)構(gòu)、性能以及隨磁場的變化情況。LMO:MgO復(fù)合薄膜上生長的YBCO薄膜與在LMO上生長的YBCO薄膜的結(jié)晶性和結(jié)構(gòu)非常接近,但LMO:MgO復(fù)合薄膜的臨界電流隨著磁場的衰減趨勢相對緩慢。
[Abstract]:YBA _ 2Cu _ 3O _ (7-x) YBCO) has the advantages of low cost, high current-carrying capacity, good mechanical strength and mass production, so the YBCO superconducting tape is stored in electric energy. In the field of electric power transmission and strong magnetic field, there is a very broad application. YBCO thin film can not grow without a high quality template layer. In order to improve the performance of YBCO films in magnetic field, LMO:MgO composite film is used as a new template layer instead of LMO film. The growth of LMO thin films and LMO:MgO composite films were studied systematically. The specific contents of this thesis include the following aspects: 1. The growth conditions of RF magnetron sputtering LMO thin films are studied by adjusting the deposition temperature, The growth window of LMO template layer was studied under the condition of sputtering power ar pressure and so on. Under the optimized process conditions, the LMO template layer film with half maximum width of 3? Is the width of the inside half of the face to be 5. 4? The surface roughness is 2 nm, which provides a high quality template layer for the YBCO superconducting layer. The influence of surface roughness of LMO thin film on the structure and properties of YBCO superconducting thin film was also studied. The structure and properties of YBCO thin film changed with the surface roughness of LMO thin film. The results show that the structure of LMO thin films is improved with the decrease of surface roughness from 7 nm to 1.3 nm. The critical current density also increased from 1 MA/cm2 to 2. 4 Ma / cm 2. 3. The growth of LMO:MgO composite films by RF magnetron sputtering was studied. The growth window of LMO:MgO composite films was further optimized by using the process conditions of LMO films as a reference. The growth of LMO:MgO composite thin films was discussed. The LMO:MgO composite films were grown on single crystal LAO substrates and on the Hultz alloy substrates with long IBAD MgO thin films, respectively. Finally, the LMO:MgO composite thin films grown roughly separately from LMO and MgO phases were obtained. YBCO superconducting thin films were grown on LMO:MgO composite films. The structure of YBCO thin films grown on two kinds of thin films was compared. The crystallinity and structure of the YBCO films grown on the LMO: MgO composite films are very close to those of the YBCO films grown on LMO, but the critical current of the LMO:MgO composite films is relatively slow with the decrease of the magnetic field.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TB383.2
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本文編號：1488472