Control of La$_{0.5}$Ca$_{0.5}$MnO$_3$ superstructure through epitaxial strain release

ORAL

Abstract

Intergranular variations of superlattice periodicity in polycrystalline La$_{1-x}$Ca$_{x}$MnO$_3$ have been attributed to variations in strain. Here we control the superlattice periodicity within a continuous crystal. A focussed ion beam microscope (FIB) was used to pattern an electron transparent window in an untwinned coherently strained epitaxial thin film of La$_{0.5}$Ca$_{0.5}$MnO$_3$ grown on NdGaO$_3$ by pulsed laser deposition. It was found that the wavenumber could be reduced by 3\% in regions isolated by cuts from the rest of the window. We attribute this variation to the release of epitaxial strain beyond the resolution of the electron microscope.

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Authors

  • S. Cox

  • E.J. Rosten

  • James Loudon

    Cambridge University

  • J.C. Chapman

  • D.-J. Kang

  • M.J. Calderon

  • Peter Littlewood

    Cambridge University, University of Cambridge, Cavendish Laboratory, TCM, University of Cambridge, Cambridge University, UK

  • P.A. Midgley

    University of Cambridge

  • N.D. Mathur

    Department of Materials Science, Cambridge University, UK, Department of Materials Science, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, UK, University of Cambridge