YBa2Cu3O7−y and YbBa2Cu3O7−y superconducting films prepared by chemical solution deposition on SrTiO3 (0 0 1) substrate

Thin superconducting films of YBa2Cu3O7−y (Y1 2 3) and YbBa2Cu3O7−y (Yb1 2 3) have been derived from metal naphthenates gels spin-coated on SrTiO3 (0 0 1) substrates. X-ray diffraction and transmission electron microscopy (TEM) show that the Yb1 2 3 film with its c-axis perpendicular to the substrate surface was epitaxially grown; while a mixture of c- and a-axis Y1 2 3 was derived on the SrTiO3 (0 0 1) substrate. High-resolution electron microscopy further reveals that the c-axis Y1 2 3 thin film was epitaxially formed, covering the substrate surface. The 90° oriented a- and c-axis Y1 2 3 components are found to form meandering grain boundaries.