Zn^2＋掺杂的YBCO薄膜的超导性能研究

摘要

采用溶胶-凝胶法在LaAlO3（LAO）单晶衬底上制备了Zn^2＋掺杂的YBCO薄膜,用X射线衍射（XRD）、高分辨透射电子显微镜（HRTEM）以及标准四引线法分别研究了Zn^2＋掺杂的YBCO薄膜的微观结构、生长取向以及超导性能。结果表明,随Zn2＋掺杂浓度的增大薄膜的临界电流密度提高,而临界转变温度下降、临界转变温区变宽;但当掺杂量〉0.5%（摩尔分数）时,会影响YBCO的c轴取向生长,导致超导性能变差。通过优化掺杂比例后得到Zn2＋掺杂0.5%（摩尔分数）的YBCO薄膜具有最好的综合超导性能,其TC为91.3K,ΔT为1.1K,Jc约为1.54MA/cm^2（77K,0T）。%Zn2＋-doped YBCO thin films were prepared on LaAlO3（LAO） single-crystal substrates by sol-gel process.The microstructure and growth orientation of the Zn2＋-doped YBCO thin films were analyzed by X-ray diffraction（XRD） and transmission electron microscopy（TEM） respectively.The standard four-probe method was used to measure the superconducting properties of the pure and doped YBCO thin films.The results show that the critical current density Jc of the Zn^2＋-doped YBCO films was improved with the increase of Zn2＋ concentration,although critical transition temperature TC was decreased and transition width ΔT was broadened.When the Zn^2＋ doping percentage is over 0.5mol%,the YBCO films exhibit deteriorated superconducting properties due to bad c-axis growth orientation.It is found that YBCO film doped with 0.5mol% Zn^2＋ show the best superconducting performance with TC of 91.3K,ΔT of 1.1K and Jc of 1.54MA/cm2（77K,0T）.