Single crystal superconducting Y sub 1 Ba sub 2 Cu sub 3 O sub (7-x) oxide films by molecular beam epitaxy.
23 June 1987
Recent breakthrough of superconductivity over 90 K in the Cu oxide based perovskite-type materials is of immense importance in both science and technology. The superconducting oxide crystals prepared in thin film form are vital for fundamental physical studies as well as for device applications. We report here the structural and superconducting properties of single crystal Y sub 1 Ba sub 2 Cu sub 3 O sub (7-x) films prepared by molecular beam epitaxy (MBE) developed for thin film semiconductor technology. The films are epitaxial crystals grown on SrTiO sub 3 (100) face with an orientation of a axis perpendicular to the film plane. Sharp resistive superconducting transitions with T sub c (R=0) above 77 K have been reproducibly achieved. The critical current densities are 10 sup 3 { A/cm sup 2} at 77 K, 5 x 10 sup 4 { A/cm sup 2} at 70 K, and wig 10 sup 6 { A/cm sup 2} at 4.2 K.