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Title: Strain accommodation through facet matching in La{sub 1.85}Sr{sub 0.15}CuO{sub 4}/Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4} ramp-edge junctions

Abstract

Scanning nano-focused X-ray diffraction and high-angle annular dark-field scanning transmission electron microscopy are used to investigate the crystal structure of ramp-edge junctions between superconducting electron-doped Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4} and superconducting hole-doped La{sub 1.85}Sr{sub 0.15}CuO{sub 4} thin films, the latter being the top layer. On the ramp, a new growth mode of La{sub 1.85}Sr{sub 0.15}CuO{sub 4} with a 3.3° tilt of the c-axis is found. We explain the tilt by developing a strain accommodation model that relies on facet matching, dictated by the ramp angle, indicating that a coherent domain boundary is formed at the interface. The possible implications of this growth mode for the creation of artificial domains in morphotropic materials are discussed.

Authors:
; ; ; ;  [1]; ;  [2]
  1. MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)
  2. Electron Microscopy for Materials Science (EMAT), Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)
Publication Date:
OSTI Identifier:
22499236
Resource Type:
Journal Article
Resource Relation:
Journal Name: APL Materials; Journal Volume: 3; Journal Issue: 8; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CRYSTAL STRUCTURE; DOPED MATERIALS; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION

Citation Formats

Hoek, M., Coneri, F., Poccia, N., Renshaw Wang, X., Hilgenkamp, H., E-mail: h.hilgenkamp@utwente.nl, Ke, X., and Van Tendeloo, G. Strain accommodation through facet matching in La{sub 1.85}Sr{sub 0.15}CuO{sub 4}/Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4} ramp-edge junctions. United States: N. p., 2015. Web. doi:10.1063/1.4927796.
Hoek, M., Coneri, F., Poccia, N., Renshaw Wang, X., Hilgenkamp, H., E-mail: h.hilgenkamp@utwente.nl, Ke, X., & Van Tendeloo, G. Strain accommodation through facet matching in La{sub 1.85}Sr{sub 0.15}CuO{sub 4}/Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4} ramp-edge junctions. United States. doi:10.1063/1.4927796.
Hoek, M., Coneri, F., Poccia, N., Renshaw Wang, X., Hilgenkamp, H., E-mail: h.hilgenkamp@utwente.nl, Ke, X., and Van Tendeloo, G. Sat . "Strain accommodation through facet matching in La{sub 1.85}Sr{sub 0.15}CuO{sub 4}/Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4} ramp-edge junctions". United States. doi:10.1063/1.4927796.
@article{osti_22499236,
title = {Strain accommodation through facet matching in La{sub 1.85}Sr{sub 0.15}CuO{sub 4}/Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4} ramp-edge junctions},
author = {Hoek, M. and Coneri, F. and Poccia, N. and Renshaw Wang, X. and Hilgenkamp, H., E-mail: h.hilgenkamp@utwente.nl and Ke, X. and Van Tendeloo, G.},
abstractNote = {Scanning nano-focused X-ray diffraction and high-angle annular dark-field scanning transmission electron microscopy are used to investigate the crystal structure of ramp-edge junctions between superconducting electron-doped Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4} and superconducting hole-doped La{sub 1.85}Sr{sub 0.15}CuO{sub 4} thin films, the latter being the top layer. On the ramp, a new growth mode of La{sub 1.85}Sr{sub 0.15}CuO{sub 4} with a 3.3° tilt of the c-axis is found. We explain the tilt by developing a strain accommodation model that relies on facet matching, dictated by the ramp angle, indicating that a coherent domain boundary is formed at the interface. The possible implications of this growth mode for the creation of artificial domains in morphotropic materials are discussed.},
doi = {10.1063/1.4927796},
journal = {APL Materials},
number = 8,
volume = 3,
place = {United States},
year = {Sat Aug 01 00:00:00 EDT 2015},
month = {Sat Aug 01 00:00:00 EDT 2015}
}
  • We used point-contact tunneling spectroscopy to study the superconducting pairing symmetry of electron-doped Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4-y} (NCCO) and hole-doped La{sub 1.89}Sr{sub 0.11}CuO{sub 4} (LSCO). Nearly identical spectra without zero bias conductance peak (ZBCP) were obtained on the (110) and (100) oriented surfaces (the so-called nodal and anti-nodal directions) of NCCO. In contrast, LSCO showed a remarkable ZBCP in the nodal direction as expected from a d-wave superconductor. Detailed analysis reveals an s-wave component in the pairing symmetry of the NCCO sample with {Delta}?k{sub B}T{sub c}=1.66, a value remarkably close to that of a weakly coupled Bardeen-Cooper-Schriffer (BCS) superconductor. Wemore » argue that this s-wave component is formed at the Fermi surface pockets centered at ({+-}{pi},0) and (0,{+-}{pi}) although a d-wave component may also exist.« less
  • High resolution angle-resolved photoemission measurements have been carried out on (La{sub 1.4 {minus}x}-Nd {sub 0.6}Sr{sub x})CuO{sub 4} , a model system with static one-dimensional (1D) charge ordering (stripe), and (La{sub 1.8 5}-Sr {sub 0.15})CuO {sub 4} , a high temperature superconductor (T{sub c}=40 K) with possible dynamic stripes. In addition to the straight segments near ({pi},0 ) and (0,{pi} ) antinodal regions, we have identified the existence of spectral weight along the [1,1] nodal direction in the electronic structure of both systems. This observation of nodal state, together with the straight segments near antinodal regions, reveals the dual nature ofmore » the electronic structure of stripes due to the competition of order and disorder.« less
  • No abstract prepared.
  • We report the thickness-dependent strain-relaxation behavior and the associated impacts upon the superconductivity in epitaxial La 1.85Sr 0.15CuO 4 films grown on different substrates, which provide a range of strain. We have found that the critical thickness for the onset of superconductivity in La 1.85Sr 0.15CuO 4 films is associated with the finite thickness effect and epitaxial strain. In particular, thin films with tensile strain greater than ~0.25% revealed no superconductivity. We attribute this phenomenon to the inherent formation of oxygen vacancies that can be minimized via strain relaxation.
  • Oxygen defect control has long been considered an important route to functionalizing complex oxide films. However, the nature of oxygen defects in thin films is often not investigated beyond basic redox chemistry. One of the model examples for oxygen-defect studies is the layered Ruddlesden–Popper phase La 2-xSr x CuO 4-δ (LSCO), in which the superconducting transition temperature is highly sensitive to epitaxial strain. However, previous observations of strain-superconductivity coupling in LSCO thin films were mainly understood in terms of elastic contributions to mechanical buckling, with minimal consideration of kinetic or thermodynamic factors. Here, we report that the oxygen nonstoichiometry commonlymore » reported for strained cuprates is mediated by the strain-modified surface exchange kinetics, rather than reduced thermodynamic oxygen formation energies. Remarkably, tensile-strained LSCO shows nearly an order of magnitude faster oxygen exchange rate than a compressively strained film, providing a strategy for developing high-performance energy materials.« less