Fabrication of YBCO Thin Films by Fluorine-Free MOCSD Method: Influence of Sintering Near the Melting Point

YBa
₂
Cu
₃
O
_7-δ
thin films were deposited by a fluorine-free metal-organic chemical solution deposition method using metal acetates as the starting materials. In this article, influence of different sintering temperatures (770-800 °C) on structural and superconducting properties of the films was investigated. Using a mixture of argon with 100 ppm oxygen as the atmosphere of the sintering process, some grain melting was observed at this temperature range, which favors to obtain a more c-axis epitaxial films with a higher critical current density. The decomposition mechanism of organic components of precursor powder was studied by Thermal Gravimetric Analysis (TGA)/Differential Scanning Calorimetry (DSC) analysis. The structural and morphological properties of the films were investigated by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM) analysis. Four-point probe and inductive third-harmonic voltage measurements were carried out to determine transition temperature and critical current density, respectively. The film sintered at 790 °C showed a superconducting transition temperature at 91.5 K with a width of 1.2 K and a critical current density of 2 MA/cm
²
.