Local piezoresponse in BiFeO3–HoFeO3 ceramics across morphotropic phase boundary

Chi Shun Tu, Pin Yi Chen, Wei Sea Chang, Wen Hao Wu, Carvyn Blaise, Yi Shin Jou

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    7 Citations (Scopus)

    Abstract

    This study highlights structural evolution, nanoscale polarization switching and electromechanical mechanisms in lead-free perovskite (1-x)BiFeO3–xHoFeO3 ceramics in the vicinity of the morphotropic phase boundary (MPB). A phase crossover from ferroelectric rhombohedral R3c phase to nonpolar orthorhombic Pnma phase is identified as the system crosses the MPB. Local electric-field switched piezoresponse microscopies indicate a decreasing switchable-polarization percentage near the MPB. Ferroelectric-relaxor phase crossover takes place within the grains, accompanied by a V-shape hysteresis loop of electromechanical strain vs. bias voltage in the vicinity of the MPB. The oxygen K-edge synchrotron X-ray absorption suggests a decreased Bi 6s2 lone pair as the system approaches the MPB, which plays an important role in modification of local ferroelectric polarization. The enhanced ferromagnetic behavior may originate from collective effects, including structural distortion, exchange interactions, suppression of antiferromagnetic spin structure, and fewer oxygen vacancies, caused by the A-site Ho substitution.

    Original languageEnglish
    Article number110626
    Number of pages10
    JournalMaterials Research Bulletin
    Volume121
    DOIs
    Publication statusPublished - Jan 2020

    Keywords

    • A. Ceramics
    • A. Structural materials
    • B. Phase transition
    • C. Atomic force microscopy
    • D. Multiferroics

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