Showing papers by "Richard E. Russo published in 1989"

Y-Ba-Cu-O superconducting films produced by long-pulse laser vaporization

Abstract: Deposition of superconducting thin films from YBa2Cu3O7 targets using a long‐pulse (ms) Nd‐glass laser with 50 J/pulse energy has been demonstrated. The deposition rate was approximately 100 nm/pulse and the film stoichiometry was close to that of the target. Scanning electron microscopy revealed spherical inclusions in the film. Scanning tunneling microscopy in air showed a terrace‐ledge structure on the uniform portion of the film. A film produced by four pulses on a SrTiO3 substrate, held at 540 °C, and post‐annealed in O2 at 850 °C for about 2h exhibited an onset transition at 78 K and zero resistance at 61 K. This new approach can provide fast deposition rates and broad‐area film coverage per laser shot.

Long Laser-Pulse Method of Producing Y-Ba-Cu-O Superconducting Films

Abstract: The quality of superconducting thin films evaporated from YBa{sub 2}Cu{sub 3}O{sub 7} targets has been improved using a long-pulse (ms) Nd-glass laser with 50 J pulse energy The film produced on SrTiO{sub 3}, held at 690 C, and post-annealed at 880 C for about three hours began the transition to superconductivity at 85 K and had zero resistance at 79 K The observed variation in film thickness corresponded to diffuse emission from the target, and no significant variation in composition as a function of angle of emission up to 40{degree} with respect to surface normal was seen