【作者】 马怀香；

【导师】 赵高扬；

【作者基本信息】 西安理工大学 ， 材料物理与化学， 2004， 硕士

【摘要】 YBCO高温超导薄膜在红外探测器、量子干涉器等众多领域有非常广阔的应用前景，目前制备这种薄膜的主要方法有磁控溅射，激光脉冲沉积等。本研究旨在采用溶胶—凝胶法制得具有钙钛矿结构的致密YBCO薄膜。以无机盐为出发原料研究了溶胶形成过程中的化学反应及成膜机理，探讨了Si基板上薄膜缓冲层的技术等。进一步用扫描电镜、透射电镜和X射线衍射仪研究了薄膜组织结构和结晶情况，分析了缓冲层和衬底对YBCO薄膜制备的影响、以及不同热处理条件对薄膜结晶结构及性能的影响。研究结果表明： （1）采用Y、Ba和Cu的无机盐为出发原料，采用乳酸、α—甲基丙烯酸及二乙烯三胺作络合剂，可以制得易于成膜且稳定性良好的无氟系YBCO溶胶。 （2）用Sol-Gel法在Si基板上制的钇稳定氧化锆（YSZ）和钛酸锶（STO）薄膜作为Si与YBCO间的缓冲层是可行的。 （3）根据本文热处理过程的工艺探索，认为热处理气氛、气流量及处理温度是影响薄膜质量及性能的重要因素，通过优化工艺过程，在钛酸锶（STO）单晶上制得的YBCO薄膜表面质量良好，室温电阻200Ω左右；而在预制了钛酸锶（STO）缓冲层的Si基板上制备的YBCO薄膜的室温电阻为300Ω左右。 （4）电子衍射表明YSZ作缓冲层制得的薄膜中具有YBa₂Cu₄O₈超导结构。XRD测试表明由溶胶制成的YBCO粉末具有YBa₂Cu₃O_7-δ超导结构。更多还原

【Abstract】 YBCO high temperature superconductor film holds great promise for applications in infrared detector,quanta interferometer and so on.Presently the main methods of preparing YBCO films have magnetron sputtering and laser deposition.In this paper the dense YBCO with perovskite structure were expected to be prepared by Sol-Gel process.The confecting methods of sol were discussed using inorganic salt as precursors,and the FT-IR was adopted to analyse the chemical reaction and film forming mechanism of stable sol. The techniques of preparing film buffer layers on Si were studied.The SEM,TEM and XRD were adopted to study the crystal structure of films. The influences of buffer layers,substrate and heat treatment condition on the crystal structure and performance of the YBCO films were discussed. The results are listed as follows:(1) The inorganic acetate of Y, Ba and Cu were used as precursors, and diethylenetriaminejactic acid and a-methacrylic acid as complexing agents, respectively.The stable fluorine-free YBCO sol can be obtained.(2) The YSZ and STO buffer layers were prepared by Sol-Gel process on Si substrates.the YSZ and STO films could be used as the buffer layers between Si substrate and YBCO films.(3) According to the study of heat treatment process, heat treatment ambience,airflow and heat treatment temperature were considerd as the important influences on the quality and property of YBCO films.Through optimizing the process,the YBCO films were prepared on STO single crystal, and their room temperature resistance was about 200 YBCO films also were fabricated on the STO buffered Si substrate,and their room temperature resistance was about 300D.(4) Through electron diffraction, it was determined the films of YBa2Cu4O8 superconducting structure had been prepared using YSZ as buffer layers. Through XRD testing,it was indicated the YBCO powder had YBa2Cu3O7- superconducting structure.更多还原