Growth and properties of YBCO thin films on polycrystalline Ag substrates by inclined substrate pulsed laser deposition

摘要

Full c-axis-oriented YBCO films were directly deposited on polycrystalline silver substrates by inclined substrate pulsed laser ablation. The orientation and microstructure of the YBCO films were characterized by x-ray diffraction 2 theta-scans. OMEGA-scans and pole figure analysis. Surface morphology was examined by scanning electron microscopy. Irregular-mosaic-shaped supergrains were observed in the films. Raman spectroscopy was used to evaluate the quality of the YBCO films. The superconducting transition temperature (T_c) and the critical current density (J_c) of the films were determined by inductive and transport measurements, respectively. T_c=91 K with sharp transition and J_c=2.7 X 10~5 A cm~(-2) at 77 K in zero field were obtained on a film that was 0.14 mu m thick, 5 mm wide and 10 mm long. This work demonstrated a promising approach to obtain high-J_c YBCO films on nontextured polycrystalline silver substrate.