Characterization of epitaxially grown YBa₂Cu₃O_7-δ thin films produced using pulsed ion-beam evaporation

Epitaxially grown YBa₂Cu₃O_7-δ (Y-123) thin films have been successfully deposited on single crystal SrTiO₃ substrates by a pulsed ion-beam evaporation (IBE) method. A cation-stoichiometric Y-123 target was bombarded by protons with an energy of 1 MeV (peak) using a pulsed ion beam generator ('ETIGO-II'). The ablation plasma was deposited on SrTiO₃ single crystal substrates. The thin films were heat-treated at 900°C for 2 h and 650°C for 5 h in flowing oxygen gas. The X-ray diffraction (XRD) pattern for an annealed thin film revealed that a single-phase, c-axis-oriented Y-123 thin film was obtained. Since a fourfold symmetry was observed in a [102] pole figure, the Y-123 thin film was concluded to be epitaxially grown on the SrTiO₃ substrate. From high-speed photographs of the time evolution of the plasma, the instantaneous deposition rate of the film was estimated to be approximately 5 mm/s.