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无氟高分子辅助金属有机物沉积法制备SmBCO超导薄膜
Preparation of SmBCO Superconducting Film by Fluorite-Free Polymer-Assisted Metal Organic Deposition
【作者】 杨新福;
【作者基本信息】 西南交通大学 , 材料科学与工程, 2012, 硕士
【摘要】 本论文综述了超导材料的发展、应用以及分类;简要介绍了REBCO高温超导薄膜的发展和制备方法;重点介绍了REBCO高温超导薄膜的结构、性能参数;并阐明了本课题的研究目的及内容。本论文采用无氟高分子辅助金属有机物沉积方法(PA-MOD)在LaA103单晶片上制备SmBa2Cu307.x(SmBCO)薄膜。首先全面介绍了制备SmBCO薄膜的整个工艺流程;其次对无氟PA-MOD法制备SmBCO薄膜的热处理工艺进行研究,通过实验确定最佳外延生长温区为790℃,然后引入部分熔融进一步优化SmBCO的外延生长工艺;对样品进行X射线衍射(XRD)分析、扫描电镜(SEM)分析以及综合物性测量系统PPMS的测试,得到的SmBCO薄膜c轴织构良好,表面平整致密;综合物性测量系统(PPMS)测试结果表明SmBCO样品的超导临界温度T。为91K左右。本文接着选取Co元素微量掺杂SmBCO薄膜(名义掺杂量分别为0.001,0.002和0.003),研究了Cu位掺杂对SmBCO薄膜超导性能的影响。采用优化后的热处理工艺制备了微量Co掺杂的SmBCO薄膜,并利用XRD、SEM、PPMS等表征手段对薄膜性能进行分析测试。结果表明,微量Co掺杂后的SmBCO薄膜的表面形貌平整致密。最后,采用多次旋涂制备SmBCO双层膜,研究SmBCO双层膜的织构和微结构,双层膜的厚度为243nm左右。
【Abstract】 In this thesis, the development, application and classification of superconducting materials were summarized.The development and fabrication methods of REBCO high temperature superconducting films were introduced.The structure, performance parameters were presented with the research goal and content.SmBa2Cu3O7-x(SmBCO)films have been synthesized on single crystal substrates of LaA103by using a fluorite-free PA-MOD method. First the whole treating process of SmBCO film fabrication has been introduced.The anneal process of using a fluorite-free PA-MOD method to synthesize SmBCO thin film was investigated. The optimal epitaxial growth temperature was790℃, and melt-partially mehod was proposed to optimize SmBCO film process. The SmBCO thin films have been investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM) and PPMS method. The results showed that exhibited high c-axis orientation, smooth, dense and crack-free surface. The PPMS test results show that the SmBCO samples of the superconducting critical temperature T c of about91K.The effect of slight Co element doping at Cu site (nominal doped level was0.001,0.002and0.003) doping on critical current densities of SmBCO films in high magnetic field was also investigated. SmBCO films with slight Co element doping have been synthesized by using the optimized fluorite-free MOD method. The SmBCO thin films have been investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM) and PPMS method. Research results show that SmBCO films with slight Co element doping displays smooth and dense surface morphology.In the last part of the thesis, a number of spin-coating preparation of SmBCO double-thick film, research of SmBCO double-layer thick film texture and microstructure, the bilayer membrane thickness of243nm.