AbstractSuperlattice structures, consisting of SrCuO2, (Sr,Ca)CuO2, and BaCuO2 layers in the tetragonal, "infinite layer" crystal structure, have been grown by pulsed-laser deposition (PLD). Superlattice chemical modulation is observed for structures with component layers as thin as a single unit cell (~3.4 Å), indicating that unit-cell control of (Sr,Ca)CuO2 growth is possible using conventional pulsed-laser deposition over a wide oxygen pressure regime. X-ray diffraction intensity oscillations, due to the finite thickness of the film, indicate that these films are extremely flat with a thickness variation of only ~20 Å over a length scale of several thousand angstroms. Using the constraint of epitaxy to grow metastable cuprates in the infinite layer structure, novel high-temperature superconducting structural families have been formed. IN particular, epitaxially-stabilized SrCuO2/BaCuO2 superlattices, grown by sequentially depositing on lattice-matched (100) SrTiO3 from BaCuO2 and SrCuO2 ablation targets in a PLD system, show metallic conductivity and superconductivity at Tc(onset) ~70 K. these results show that pulsed-laser deposition and epitaxial stabilization have been used to effectively "engineer" artificially-layered thin-film materials.
A Superconducting Praseodymium Nickelate with Infinite Layer Structure
