Venkateshwarlu, Sarangi ; Kodumudi Venkataraman, Lalitha ; Segouin, Valentin ; Marlton, Frederick P. ; Hin, Ho Chin ; Chernyshov, Dmitry ; Ren, Yang ; Jorgensen, Mads R. V. ; Nayak, Sanjib ; Rödel, Jürgen ; Daniel, Laurent ; Pramanick, Abhijit (2020)
Large electromechanical strain and unconventionaldomain switching near phase convergencein a Pb-free ferroelectric.
In: Communications Physics, 3 (193)
doi: 10.1038/s42005-020-00459-2
Artikel, Bibliographie

Kurzbeschreibung (Abstract)

In many ferroelectrics, large electromechanical strains are observed near regions of com-position- or temperature- driven phase coexistence. Phenomenologically, this is attributed toeasy re-orientation of the polarization vector and/or phase transition, although their effectsare highly convoluted and difficult to distinguish experimentally. Here, we used synchrotronX-ray scattering and digital image correlation to differentiate between the microscopicmechanisms leading to large electrostrains in an exemplary Pb-free piezoceramic Sn-dopedbarium calcium zirconate titanate. Large electrostrains of ~0.2% measured at room-temperature are attributed to an unconventional effect, wherein polarization switching isaided by a reversible phase transition near the tetragonal-orthorhombic phase boundary.Additionally, electrostrains of ~0.1% or more could be maintained from room temperature to140 °C due to a succession of different microscopic mechanisms. In situ X-ray diffractionelucidates that while 90° domain reorientation is pertinent below the Curie temperature (TC),isotropic distortion of polar clusters is the dominant mechanism above TC.

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