Anomalous Skin Effect in the Lead-Free Relaxor NBT

ORAL

Abstract

Several x-ray and neutron powder diffraction studies have shown that the room-temperature space group of the lead-free relaxor NBT is monoclinic Cc and not rhombohedral R3c, as was previously believed. Motivated by these findings, we performed room-temperature neutron scattering measurements on a large (3.5 gram) single crystal of the lead-free relaxor NBT. Our data confirm the R3c symmetry for bulk NBT and place a strict bound on the strength of the 1/2(111) superlattice reflection associated with the Cc space group based on the published atomic coordinates. We show that a skin effect, analogous to that reported in the relaxors PZN and PMN-10\%PT, can reconcile our single-crystal data with these other studied. We believe this represents the first evidence of the relaxor skin effect in a lead-free relaxor.

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Authors

  • Peter Gehring

    • National Institute of Standards and Technology
    • NIST Center for Neutron Research

  • Wenwei Ge

    • Virginia Polytechnic and State University

  • Daniel Phelan

    • University of Minnesota

  • Qinhui Zhang

    • Shanghai Institute of Ceramics, Chinese Academy of Sciences

  • Jie Fang Li

    • Virginia Polytechnic and State University

  • Dwight Viehland

    • Virginia Polytechnic and State University

  • Hasuo Luo

    • Shanghai Institute of Ceramics, Chinese Academy of Sciences

  • Lynn Boatner

    • Oak Ridge National Laboratory
    • Oak Ridge National Lab