A Molecular Dynamics Study of Dielectric Response in a Relaxor Ferroelectric

ORAL

Abstract

We use atomistic molecular dynamics simulations to study relaxor behavior in the 0.75Pb(Mg,Nb)O$_3$-0.25PbTiO$_3$ material. Even for a fairly small simulation size of 1000 atoms, the system exhibits frequency dispersion and deviation from the Curie-Weiss law typical of relaxor materials. Analysis of the time autocorrelation functions for individual atoms allows us to identify the Nb atoms with a high concentration of neighboring Ti atoms as the nucleation sites for the relaxor behavior. This is due to the higher coupling between the cation displacements induced by the presence of overbonded oxygen atoms located between Nb and Ti atoms.

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Authors

  • Andrew Rappe

    The Makineni Theoretical Laboratories, Deparment of Chemistry, University of Pennsylvania, The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, University of Pennsylvania, The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA

  • Ilya Grinberg

    University of Pennsylvania

  • Young-Han Shin

    University of Ulsan