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Changes in phonon dispersion across metal-insulator transition in a Pr-containing cobaltite

ORAL

Abstract

A group of praseodymium-containing cobaltites are known to undergo 1st order metal-insulator transitions that are correlated to valence shifts that involve both Pr and Co cations. We have measured the dispersion of acoustic phonons in a single crystal of (Pr0.85Y0.15)0.7Ca0.3CoO3-δ in both the metallic and insulating states and have observed differences which arise at the phase transition temperature. We interpret changes in the mode energies in terms of changes in the elastic constants. Anomalous damping of the phonons is observed near the phase transition. Elastic diffuse scattering, symptomatic of precursory behavior in the metallic phase is observed.

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Presenters

  • Daniel Phelan

    Materials Science Division, Argonne National Lab, Argonne Natl Lab, Materials Science Division, Argonne National Laboratory, Material Science, Argonne National Laboratory

Authors

  • Daniel Phelan

    Materials Science Division, Argonne National Lab, Argonne Natl Lab, Materials Science Division, Argonne National Laboratory, Material Science, Argonne National Laboratory

  • Matthew Krogstad

    Argonne National Laboratory, Argonne National Lab, Material Science Division, Argonne National Laboratory, Materials Science Division, Argonne National Lab, Materials Science Division, Argonne National Laboratory, Material Science, Argonne National Laboratory

  • Nathaniel Schreiber

    Cornell University, Department of Materials Science and Engineering, Cornell University, Department of Materials Science and Engineering, Kavli Institute at Cornell for Nanoscale Science, Cornell University

  • Raymond Osborn

    Argonne National Laboratory, Argonne National Lab, Material Science Division, Argonne National Laboratory, Materials Science Division, Argonne National Lab, Materials Science Division, Argonne National Laboratory, Material Science, Argonne National Laboratory

  • Ayman Said

    APS, Argonne National Laboratory, Advanced Photon Source, Argonne National Laboratory

  • Hong Zheng

    Argonne National Laboratory, Argonne Natl Lab, Materials Science Division, Argonne National Laboratory, Material Science Division, Argonne National Lab

  • Stephan Rosenkranz

    Materials Science Division, Argonne National Lab, Argonne National Laboratory, Argonne National Lab, Material Science Division, Argonne National Laboratory, Materials Science Division, Argonne National Laboratory, Argonne Natl Lab, Material Science, Argonne National Laboratory