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.
*This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Science, Materials Science and Engineering Division. This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
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Presenters
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Daniel Phelan
- Argonne National Laboratory
- Materials Science Division, Argonne National Lab
- Material Science, Argonne National Laboratory