Structural, magnetic, and superconducting properties of pulsed-laser-deposition-grown ${\text{La}}_{1.85}$ ${\text{Sr}}_{0.15}$ ${\text{CuO}}_4$ / ${\text{La}}_{2/3}$ ${\text{Ca}}_{1/3}$ ${\text{MnO}}_3$ superlattices on (001)-oriented ${\text{LaSrAlO}}_4$ substrates

Journal Article · 12 March 2014 · Physical Review. B, Condensed Matter and Materials Physics

DOI: https://doi.org/10.1103/PhysRevB.89.094511 · OSTI ID:1162071

Das, S. ^[1]; Sen, K. ^[1]; Marozau, I. ^[1]; Uribe-Laverde, M. A. ^[1]; Biskup, N. ^[2]; Varela, M. ^[3]; Khaydukov, Y. ^[4]; Soltwedel, O. ^[4]; Keller, T. ^[4]; Döbeli, M. ^[5]; Schneider, C. W. ^[6]; Bernhard, C. ^[1]

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1. Univ. of Fribourg, Fribourg (Switzerland). Department of Physics and Fribourg Center for Nanomaterials
2. Univ. Complutense de Madrid (Spain). Departamento Fisica Aplicada III and Instituto Pluridisciplinar
3. Univ. Complutense de Madrid (Spain). Departamento Fisica Aplicada III and Instituto Pluridisciplinar; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division
4. Max planck Institute for Solid State Research, Stuttgart (Germany); Max Planck Society, Garching (Germany). Neutron source Heinz Maier-Leibnitz (FRM-II)
5. ETH Zurich, Zurich (Switzerland). Laboratory of Ion Beam Physics
6. Paul Scherrer Inst. (PSI), Villigen (Switzerland)

Epitaxial ${\text{La}}_{1.85}$ ${\text{Sr}}_{0.15}$ ${\text{CuO}}_4$ / ${\text{La}}_{2/3}$ ${\text{Ca}}_{1/3}$ ${\text{MnO}}_3$ (LSCO/LCMO) superlattices (SL) on (001)- oriented LaSrAlO₄ substrates have been grown with pulsed laser deposition (PLD) technique. Their structural, magnetic and superconducting properties have been determined with in-situ reflection high energy electron diffraction (RHEED), x-ray diffraction, specular neutron reflectometry, scanning transmission electron microscopy (STEM), electric transport, and magnetization measurements. We find that despite the large mismatch between the in-plane lattice parameters of LSCO (a = 0.3779 nm) and LCMO (a = 0.387 nm) these superlattices can be grown epitaxially and with a high crystalline quality. While the first LSCO layer remains clamped to the LSAO substrate, a sizeable strain relaxation occurs already in the first LCMO layer. The following LSCO and LCMO layers adopt a nearly balanced state in which the tensile and compressive strain effects yield alternating in-plane lattice parameters with an almost constant average value. No major defects are observed in the LSCO layers, while a significant number of vertical antiphase boundaries are found in the LCMO layers. The LSCO layers remain superconducting with a relatively high superconducting onset temperature of T_c^onset ≈ 36 K. The macroscopic superconducting response is also evident in the magnetization data due to a weak diamagnetic signal below 10 K for H ∥ ab and a sizeable paramagnetic shift for H ∥ c that can be explained in terms of a vortex-pinning-induced flux compression. The LCMO layers maintain a strongly ferromagnetic state with a Curie temperature of T^Curie ≈ 190 K and a large low-temperature saturation moment of about 3.5 (1) μ_B. These results suggest that the LSCO/LCMO superlattices can be used to study the interaction between the antagonistic ferromagnetic and superconducting orders and, in combination with previous studies on YBCO/LCMO superlattices, may allow one to identify the relevant mechanisms.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1162071
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 89, Issue 9; ISSN 1098-0121
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English