Preparation of epitaxial YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// thin films by pulsed ion-beam evaporation

Abstract

The epitaxially grown YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (Y-123) thin films have been successfully deposited on single crystal SrTiO/sub 3/ substrates by a pulsed ion-beam evaporation method (IBE). 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 SrTiO/sub 3/ single crystal substrates. The thin films were heat-treated at 900/spl deg/C for 2 h and 650/spl deg/C for 5 h in flowing oxygen gas. The X-ray diffraction pattern for an annealed thin film revealed that a single-phase, c-axis-oriented Y-123 thin film was obtained. Since a four-fold symmetry was observed in a [102] pole figure, the Y-123 thin film was concluded to be epitaxially grown on the SrTiO/sub 3/ substrate. From high-speed photographs of the evolution of plasma, the instantaneous deposition rate of the film was estimated to be approximately 4 mm/s.