This work presents a promising method to fabricate fluorine-free GdBa₂Cu₃O_7-x (GdBCO) films on LaAlO₃ (LAO) substrate using a sol-gel technique. The phase transformation during the fabrication process and the influence of sintering parameters including crystallization temperature and oxygen partial pressure on the microstructure and superconductivity were investigated by X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy. The c-axis oriented microstructure of GdBCO films was obtained under the crystallization temperature of 820 °C and oxygen partial pressure of 1.16%. The barium-containing BaCO₃ phase can transform into Ba(OH)₂, which contributed to the formation of fluorine-free GdBCO. Moreover, scanning transmission electron microscope characterization revealed that stacking defects were formed near the LAO substrate and spread throughout the whole GdBCO matrix with weak superconductivity regions, which acted as effective pinning centers to inhibit flux creep. This resulted in a stronger current-carrying capacity of the GdBCO film than that of YBa₂Cu₃O_7-x (YBCO) film. Finally, a sustainable GdBCO film with the superconducting transition temperature (T_c) of 90 K and the critical current density (J_c) of 1.23 MA/cm² (77 K, 0 T) was achieved through a simple and effective fluorine-free sol-gel method.

这项工作提出了一种有前途的方法，利用溶胶-凝胶技术在LaAlO ₃（LAO）衬底上制备无氟的GdBa ₂ Cu ₃ O _7-x（GdBCO）膜。通过X射线衍射，扫描电子显微镜和高分辨率透射电子显微镜研究了制造过程中的相变以及包括结晶温度和氧分压在内的烧结参数对组织和超导性的影响。在820℃的结晶温度和1.16％的氧分压下获得了GdBCO膜的c轴取向微结构。含钡的BaCO ₃相可以转化为Ba（OH）₂，这有助于形成无氟的GdBCO。此外，扫描透射电子显微镜表征表明，堆叠缺陷形成于LAO衬底附近，并散布在具有弱超导区域的整个GdBCO矩阵中，这些区域充当抑制通量蠕变的有效钉扎中心。这导致GdBCO膜的载流能力强于YBa ₂ Cu ₃ O _7-x（YBCO）膜。最后，获得一种可持续的GdBCO薄膜，其超导转变温度（T _c）为90 K，临界电流密度（J _c）为1.23 MA / cm ^2。 通过简单有效的无氟溶胶-凝胶法获得了（77 K，0 T）。