Microwave Conductivity of Ferroelectric Domain Walls in BiFeO3 Bulk Crystals

ORAL

Abstract

Domain walls (DWs) in multiferroic materials exhibit novel functionalities that may be utilized for nanoelectronic applications. In recent years, the enhanced DW dc conductivity due to the accumulation of free carriers and ac conductivity due to the excitation of wall vibration have both been reported in various ferroelectrics. Combining piezo-force microscopy and microwave impedance microscopy, we directly probe the nanoscale dielectric response of various DWs in BiFeO3 bulk crystals at microwave frequencies. Interestingly, regardless of the type of the walls (71-, 109-, or 180-degree), the neutral DWs always display high ac conductivity around 1 GHz, whereas the charged walls do not. In addition, interference of surface acoustic waves can be observed near the 180-degree walls. Our results provide a unified picture to understand the DW dynamics in BiFeO3, which is crucial for its application in high-speed nano-devices.

–

Presenters

  • Lu Zheng

    University of Texas at Austin

Authors

  • Lu Zheng

    University of Texas at Austin

  • Xiaochen Fang

    Rutgers University

  • Xianghan Xu

    Rutgers University, Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Rutgers University, New Brunswick

  • Sang-Wook Cheong

    Rutgers University, Department of Physics and Astronomy, Rutgers University, Rutgers University, New Brunswick, Rutgers Center for Emergent Materials and Department of Physics & Astronomy, Rutgers University, Center for Quantum Materials Synthesis and Department of Physics and Astronomy, Rutgers, the State University of New Jersey, Department of Physics, Rutgers University, Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, USA, Physics, Rutgers University, Physics and Astronomy, Rutgers University, New Brunswick, Department of Physics and Astronomy, Rutgers University, New Jersey, Rutgers University, Physics and Astronomy, and Laboratory for Pohang Emergent Materials and Max Plank POSTECH Center for Complex Phase Materials, Pohang University of Science, RCEM, Department of Physics and Astronomy, Rutgers U., Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Department of Physics and Astronomy, 136 Frelinghuysen Road, Piscataway, New Jersey 08854, USA, Rutgers Center for Emergent Materials

  • Keji Lai

    University of Texas at Austin, Department of Physics, The University of Texas at Austin