Infinite-layer copper-oxide laser-ablated thin films: substrate, buffer-layer, and processing effects

Abstract

Laser-ablation studies of highly-oriented thin films of the electon-doped infinite-layer copper-oxide compounds Sr 1 La CuO 2 are reported. We observe significant variations in film properties with substrate or buffer layer material. X-ray diffraction, atomic force microscopy (AFM), Rutherford back-scattering (RBS), and electrical resistivity were used to characterize the films. Films were deposited on strontium titanate (001) or on buffer layers of -phase copper oxides (Ln 2 CuO 4 with Ln = Pr, Nd, Sm), Sr 3 FeNb 2 O 9 , and La 1 8 Y 0 2 CuO 4 on SrTiO 3 (001). The in-plane lattice constants of such buffer layers ( = 0 390-0 400 nm) should provide the bond tension required for electron doping. Extremely flat, epitaxial buffer layers with X-ray rocking curves as narrow as 0.08 were obtained from stoichiometric targets of Ln 2 CuO 4 ; the other buffer layers yielded poor epitaxy. A linear dependence of infinite-layer -axis plane spacing on substrate or buffer-layer in-plane -axis lattice constant is observed.

Properties of the electron-doped infinite-layer superconductor Sr1−xLaxCuO2Tomaschko1, Leca2, Selistrovski3 et al. 2012Phys. Rev. B182100View full textAdd to dashboardCite

“…sec. III C 3), in particular the same maximum T c ≈ 20 K, whereupon tensile strain was believed to enhance electron doping of the CuO 2 -planes and therefore increase T c 7,17,19,22 . For illustration, Fig.…”

“…Therefore, the idea was to enhance the electron-doping effect by epitaxial strain. Different buffer layers, such as T ′ -compounds (Ln III 2 CuO 4 ) or BaTiO 3 (BTO), with increased in-plane lattice constants were subsequently introduced to induce relaxed or tensile strained films [17][18][19][20][21] . Indeed, superconducting IL films were fabricated with this method, however still with reduced T c .…”

Continuous Flow Copper Laser Ablation Synthesis of Copper(I and II) Oxide Nanoparticles in Water

“…Batch processing is typically used in the fabrication of copper oxide nanoparticles, but such processing can result in variation of product from batch to batch, and refined reagents are required. An alternative approach to prepare different metal oxides in general involves the use of lasers, and this includes in the synthesis of copper oxide nanoparticles. − Pulsed laser ablation (PLA) involves ablating a solid target in a liquid phase or in air, which has a number of advantages. These include (a) not requiring the process to be operating under a high vacuum, (b) the processing is simple and high yielding, and (c) it avoids the use of chemicals.…”