Neutron Scattering Study on Low Energy Phonons in BiFeO$_3$

ORAL

Abstract

We have performed neutron scattering studies on low energy phonon modes in the multiferroic BiFeO$_3$. We show measurements near (100), (110), (200) Bragg peaks on the TA, LA and lowest energy TO modes in a broad temperature range from 300 K to 700 K. The intensities, dispersion, and life times (inversed energy width) of these phonon modes are plotted vs. temperature, and anomalies related to the AFM order (Neel temperature of 640 K) are discussed. We also will also discuss additional low energy modes observed that may be related to the ``electro-magnon'' excitations in this material. This work is supported by the Office of Basic Energy Sciences, DOE.

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Authors

  • Guangyong Xu

    Brookhaven Natl Lab

  • Zhijun Xu

    University of California, Berkeley, UC Berkeley

  • Jinsheng Wen

    Nanjing University

  • Peter Gehring

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

  • Stephen Shapiro

    Brookhaven Natl Lab

  • Masaaki Matsuda

    Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak RIdge Natl Lab, Oak Ridge National Lab

  • Toshimitsu Ito

    AIST

  • Robert Birgeneau

    UC Berkeley

  • Barry Winn

    Oak RIdge Natl Lab, Oak Ridge Natl Lab

  • Genda Gu

    Brookhaven National Laboratory, Condensed Matter Physics and Materials Science Department, Brookhaven National laboratory, Brookhaven Natl Lab, Brookhaven National Lab, Brookhaven National Labs