Thickness dependence of La2−xSrxCuO4 films

Abstract

Pulsed laser deposition was used to grow c-axis aligned films of La2−xSrxCuO4−δ, with Sr content, x, in the range of 0.03 to 0.2, on substrates prepared from single-crystalline SrLaAlO4, with a lattice mismatch of 0.5%. The thickness dependence of Tc0, the temperature at which the resistance falls to zero, is much reduced compared to that of films deposited on SrTiO3, where the lattice mismatch is 3.4%. The maximum Tc0 is achieved at x=0.15 for both types of substrates. While the thickness dependence is related to the strain resulting from the lattice mismatch, the value of the maximum Tc0 is determined by the oxygen concentration.

Epitaxially Induced Defects in Sr- and O-doped La2CuO4Thin Films Grown by MBE: Implications for Transport Properties

“…3. These data are in very good agreement with those recently reported for codeposited (MBE) [37], sputtered [38,39] and laser-ablated '214' thin films [40,41]. Although there is an experimental error (±0.01 Å) in the determination of the α-axis lattice parameter for the thin films, a comparison between the data for films and bulk materials indicates an average difference of 0.03-0.06 Å , which increases with the strontium content in the range 0.07 < x < 0.24.…”

“…The use of a substrate imposing a compressive epitaxial strain (SLAO) for the preparation of superconducting '214' thin films was reported a few years ago [40]. In Fig.…”

High Quality (100) and (001) Oriented Substrates Prepared from Czochralski Grown SrLaGaO4and SrLaAlO4Single Crystals

“…SrLaΑlO4 and SrLaGaO4 are currently considered [2][3][4][5][6] as some of the best substrate materials for the epitaxy of high-Τc superconductors. Taking into account the small mismatch between the substrate and HTSC layers, the application areas include: -(001) oriented SrLaGaO4 for the deposition of YBaCuO [2,3], and 1212 and 1223 phases of Hg based superconductors [4] with c-axis perpendicular to the substrate surface, -(100) oriented SrLaGaO 4 for the deposition of YBaCuO [5], and 1212 mercury films with c-axis parallel to the substrate surface, -(001) oriented SrLaΑlO4 [6] for the deposition of La2-x Srx CuO4.…”

Strain Relaxation in Thin Films of La1.85Sr0.15CuO4Grown by Pulsed Laser Deposition

“…If the films are grown heteroepitaxially on the substrates with the mismatched lattice parameters, their quality may be compromised as a result of strain relaxation and accumulation of various growth-induced defects. The growth of thin La 1.85 Sr 0.15 CuO 4 (LSCO) films on a substrate of SrLaAlO 4 (SLAO) is known to produce films with compressive in-plane strain which enhances superconducting transition temperature, T c [1][2][3][4]. However, the thick LSCO films grown on SLAO suffer film-to-film variations of T c and other transport parameters [5][6][7].…”