Growth of high-quality ErBa₂Cu₃O_7-δ thin films

ErBa₂Cu₃O_7-δ thin films are grown by pulsed laser deposition (PLD). Using a SrTiO₃ as a lattice matched substrate. In the film growth, the substrate temperature is varied from 720 to 780 °C. From X-ray diffraction (XRD) patterns, only the 00l reflections from the ErBa₂Cu₃O_7-δ films are observed. The average of the c-axis length of the other films is 11.6875 Å. ErBa ₂Cu₃O_7-δ film grown at 735 °C is excellent in the crystallinity, while the intensity of 00l peaks of the film grown at more than 780 °C obviously weakened. The zero resistance T _c is 90.5 K. Superconducting transition width is 1.5 K. Large and flat grains are observed by atomic force microscopy (AFM) at the surface of the film. From the scanning electron microscope (SEM) image, we confirmed some grains with the size of approximately 200 nm in diameter on the ErBa ₂Cu₃O_7-δ thin film. We observe the interface of ErBa₂Cu₃O_7-δ and substrate clearly by transmission electron microscopy (TEM) measurements.