高分子辅助化学溶液沉积法制备涂层导体缓冲层和超导层
发布时间：2019-01-19 08:38
【摘要】：涂层导体的制备技术和大规模工业应用是当前超导材料研究的热点。本论文基于涂层导体实用化进程中的织构优良,致密度高,载流能力强的要求,以涂层导体缓冲层和超导层的化学制备技术为研究对象,开发出了一系列低成本、高效率的制备高性能涂层导体的技术。通过对具有自主知识产权的REBiO3缓冲层材料的RE位进行掺杂获得了一系列新型的缓冲层材料,并得到了表面具有不同形状的纳米颗粒析出相的Sm0.5Ca0.5BiO3和Eu0.6Sr0.4BiO3缓冲层材料,取得了一些有意义的结果。 论文第1章阐述了涂层导体研究开发的科学意义和实用价值,重点归纳与介绍了当前主流的缓冲层材料与制备技术。 第2章系统地阐述了第二代高温超导带材(即涂层导体)的基本实验原理与方法。重点介绍了化学溶液沉积技术和外延生长机理。对该技术的分类、前驱物、制胶的工艺流程等进行了阐述。 第3章对本论文涉及的实验方法和表征手段进行了阐述。实验方法方面,介绍了高分子辅助化学溶液沉积(PA-CSD)法制备涂层导体缓冲层与超导层的一般流程与相关技术参数。表征手段方面,对本论文涉及的相结构、微结构、电磁性能表征的手段进行了介绍。 第4章重点介绍了SmBiO3缓冲层在单晶基底LaA1O3以及在NiO缓冲层上的PA-CSD法的制备技术。并且初步成功地完成了NiW/NiO (SOE)/SmBiO3(PA-CSD)/YBCO(PA-CSD)这种新颖与低成本的涂层导体结构的制备工作。随后介绍了一系列PA-CSD法制备传统缓冲层BaZrO3、SrZrO3、La2Zr207、以及导电缓冲层La0.7Sr0.3MnO3的技术,研究了各自的最佳热处理工艺路线。结合高分子添加剂的化学性质和热力学特性提出了一种解释单次涂敷临界厚度提高的机制。结果表明,高分子辅助沉积制备技术是一种成本低廉、易于推广的缓冲层制备技术。最后,在REBiO3缓冲层基础上,介绍了REBiO3中的RE位用Ca或Pb替代的研究工作。并据此在LaA1O3(100)单晶基底上制得织构良好、表面平整致密的Sm1-xCaxBiO3Eu1-xCaxBiO3、Gd1-xCaxBiO3、Gd1-xPbxBiO3外延薄膜,这为调节REBiO3的晶格和导电性提供了新的途径,并得到了一系列新型的缓冲层材料。此外,在本章中特别介绍了缓冲层材料Sm0.5Ca0.5BiO3和Eu0.6Sr0.4BiO3.在其表面可以制备出纳米级的不同形状的析出相,进而可能作为钉扎中心来研究其对YBCO涂层导体在磁场下的临界电流密度的影响。 第5章讨论了EuBa2Cu3O7-x (EuBCO)薄膜在单晶基底LaA1O3(100)上的PA-CSD法的制备技术。利用自主开发的基于金属乙酸盐的高分子辅助无氟化学溶液沉积技术,在氮气气氛中LaAIOa (100)单晶基底上生长了EuBCO薄膜。通过对热处理过程进行优化,制得了厚度为290nm、双轴织构良好、表面致密平整和无微裂纹的EuBCO薄膜,且临界超导转变温度为91K,77K自场下的临界电流密度约为2.4MA/cm2。最后,对用PA-CSD法的制备超导薄膜的面内面外取向生长机理作了详细的讨论与解释。
[Abstract]:The preparation technology and large-scale industrial application of coated conductors are the hot spots in the research of superconducting materials. Based on the requirements of good texture, high density and high current carrying capacity in the practical process of coating conductor, a series of low cost have been developed based on the chemical preparation technology of coating conductor buffer layer and superconducting layer. Efficient preparation of high performance coated conductors. A series of novel buffer layer materials were obtained by doping RE sites of REBiO3 buffer layer materials with independent intellectual property rights. Sm0.5Ca0.5BiO3 and Eu0.6Sr0.4BiO3 buffer layer materials with different shapes of precipitates were obtained, and some significant results were obtained. In chapter 1, the scientific significance and practical value of the research and development of coated conductors are described, and the current mainstream buffer layer materials and preparation techniques are summarized and introduced emphatically. In chapter 2, the basic experimental principle and method of the second generation high temperature superconducting tape (i.e. coated conductor) are systematically described. The chemical solution deposition technology and epitaxial growth mechanism are introduced in detail. The classification, precursor and technological process of this technology are described. Chapter 3 describes the experimental methods and characterization methods involved in this paper. In terms of experimental methods, the general process and related technical parameters of polymer assisted chemical solution deposition (PA-CSD) for preparation of buffer layer and superconducting layer of coating conductor are introduced. In the aspect of characterization, the phase structure, microstructure and electromagnetic properties of this paper are introduced. In chapter 4, the preparation technology of SmBiO3 buffer layer on single crystal substrate LaA1O3 and on NiO buffer layer by PA-CSD method is introduced. NiW/NiO (SOE) / SmBiO3 (PA-CSD) / YBCO (PA-CSD), a novel and low cost coated conductor structure, has been successfully prepared. Then a series of techniques of preparing traditional buffer layer BaZrO3,SrZrO3,La2Zr207, and conductive buffer layer La0.7Sr0.3MnO3 by PA-CSD method are introduced and their optimal heat treatment processes are studied. Based on the chemical and thermodynamic properties of polymer additives, a mechanism is proposed to explain the increase of critical thickness of single coating. The results show that polymer assisted deposition is a low cost and easy to be popularized buffer layer preparation technology. Finally, on the basis of REBiO3 buffer layer, the research work of replacing RE bits with Ca or Pb in REBiO3 is introduced. On the basis of this, Sm1-xCaxBiO3Eu1-xCaxBiO3,Gd1-xPbxBiO3 epitaxial films with good texture and smooth and compact surface were prepared on LaA1O3 (100) single crystal substrates, which provided a new way to regulate the lattice and conductivity of REBiO3. A series of new buffer layer materials were obtained. In addition, in this chapter, the buffer layer materials Sm0.5Ca0.5BiO3 and Eu0.6Sr0.4BiO3. are introduced in particular. Nanoscale precipitates with different shapes can be prepared on the surface, which may serve as pinning centers to study the effect of nanoscale precipitates on the critical current density of YBCO coating conductors in magnetic field. In chapter 5, the preparation technology of EuBa2Cu3O7-x (EuBCO) thin films on LaA1O3 (100) single crystal substrate by PA-CSD method is discussed. EuBCO thin films were grown on LaAIOa (100) single crystal substrates in nitrogen atmosphere by polymeric polymer assisted fluorine-free chemical solution deposition based on metal acetate. By optimizing the heat treatment process, the EuBCO thin films with a thickness of 290 nm, good biaxial texture, compact and flat surface and no microcracks have been prepared. The critical current density of the superconducting films is about 2.4 Ma / cm ~ (2) at 91K ~ (77) K self-field. Finally, the in-plane and out-of-plane orientation growth mechanism of superconducting thin films prepared by PA-CSD method is discussed and explained in detail.
【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TB306
本文编号：2411193
[Abstract]:The preparation technology and large-scale industrial application of coated conductors are the hot spots in the research of superconducting materials. Based on the requirements of good texture, high density and high current carrying capacity in the practical process of coating conductor, a series of low cost have been developed based on the chemical preparation technology of coating conductor buffer layer and superconducting layer. Efficient preparation of high performance coated conductors. A series of novel buffer layer materials were obtained by doping RE sites of REBiO3 buffer layer materials with independent intellectual property rights. Sm0.5Ca0.5BiO3 and Eu0.6Sr0.4BiO3 buffer layer materials with different shapes of precipitates were obtained, and some significant results were obtained. In chapter 1, the scientific significance and practical value of the research and development of coated conductors are described, and the current mainstream buffer layer materials and preparation techniques are summarized and introduced emphatically. In chapter 2, the basic experimental principle and method of the second generation high temperature superconducting tape (i.e. coated conductor) are systematically described. The chemical solution deposition technology and epitaxial growth mechanism are introduced in detail. The classification, precursor and technological process of this technology are described. Chapter 3 describes the experimental methods and characterization methods involved in this paper. In terms of experimental methods, the general process and related technical parameters of polymer assisted chemical solution deposition (PA-CSD) for preparation of buffer layer and superconducting layer of coating conductor are introduced. In the aspect of characterization, the phase structure, microstructure and electromagnetic properties of this paper are introduced. In chapter 4, the preparation technology of SmBiO3 buffer layer on single crystal substrate LaA1O3 and on NiO buffer layer by PA-CSD method is introduced. NiW/NiO (SOE) / SmBiO3 (PA-CSD) / YBCO (PA-CSD), a novel and low cost coated conductor structure, has been successfully prepared. Then a series of techniques of preparing traditional buffer layer BaZrO3,SrZrO3,La2Zr207, and conductive buffer layer La0.7Sr0.3MnO3 by PA-CSD method are introduced and their optimal heat treatment processes are studied. Based on the chemical and thermodynamic properties of polymer additives, a mechanism is proposed to explain the increase of critical thickness of single coating. The results show that polymer assisted deposition is a low cost and easy to be popularized buffer layer preparation technology. Finally, on the basis of REBiO3 buffer layer, the research work of replacing RE bits with Ca or Pb in REBiO3 is introduced. On the basis of this, Sm1-xCaxBiO3Eu1-xCaxBiO3,Gd1-xPbxBiO3 epitaxial films with good texture and smooth and compact surface were prepared on LaA1O3 (100) single crystal substrates, which provided a new way to regulate the lattice and conductivity of REBiO3. A series of new buffer layer materials were obtained. In addition, in this chapter, the buffer layer materials Sm0.5Ca0.5BiO3 and Eu0.6Sr0.4BiO3. are introduced in particular. Nanoscale precipitates with different shapes can be prepared on the surface, which may serve as pinning centers to study the effect of nanoscale precipitates on the critical current density of YBCO coating conductors in magnetic field. In chapter 5, the preparation technology of EuBa2Cu3O7-x (EuBCO) thin films on LaA1O3 (100) single crystal substrate by PA-CSD method is discussed. EuBCO thin films were grown on LaAIOa (100) single crystal substrates in nitrogen atmosphere by polymeric polymer assisted fluorine-free chemical solution deposition based on metal acetate. By optimizing the heat treatment process, the EuBCO thin films with a thickness of 290 nm, good biaxial texture, compact and flat surface and no microcracks have been prepared. The critical current density of the superconducting films is about 2.4 Ma / cm ~ (2) at 91K ~ (77) K self-field. Finally, the in-plane and out-of-plane orientation growth mechanism of superconducting thin films prepared by PA-CSD method is discussed and explained in detail.
【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TB306
【参考文献】
相关期刊论文 前4条
1 秦冬阳;卢亚锋;张孔;刘茜;周廉;;ω扫描和φ扫描在薄膜结构表征中的应用[J];材料导报;2011年14期
2 师晓燕;蒲明华;王文涛;赵勇;;无氟MOD法制备DyBa_2Cu_3O_(7-x)膜的高温热处理过程研究[J];稀有金属材料与工程;2010年04期
3 张红;赵勇;张欣;王贺龙;蒲明华;潘敏;;超导涂层导体中NiO缓冲层的制备与研究[J];功能材料;2011年05期
4 赵忠贤,陈立泉,崔长庚,黄玉珍,刘锦湘,陈赓华,李山林,郭树权,何业冶;Sr(Ba)-La-Cu氧化物的高临界温度超导电性[J];科学通报;1987年03期
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