Nanoscale mechanical switching of ferroelectric polarization via flexoelectricity

Yijia Gu, Zijian Hong, Jason Britson, Long Qing Chen

Research output: Contribution to journalArticle

35 Scopus citations

Abstract

Flexoelectric coefficient is a fourth-rank tensor arising from the coupling between strain gradient and electric polarization and thus exists in all crystals. It is generally ignored for macroscopic crystals due to its small magnitude. However, at the nanoscale, flexoelectric contributions may become significant and can potentially be utilized for device applications. Using the phase-field method, we study the mechanical switching of electric polarization in ferroelectric thin films by a strain gradient created via an atomic force microscope tip. Our simulation results show good agreement with existing experimental observations. We examine the competition between the piezoelectric and flexoelectric effects and provide an understanding of the role of flexoelectricity in the polarization switching. Also, by changing the pressure and film thickness, we reveal that the flexoelectric field at the film bottom can be used as a criterion to determine whether domain switching may happen under a mechanical force.

Original languageEnglish (US)
Article number022904
JournalApplied Physics Letters
Volume106
Issue number2
DOIs
StatePublished - Jan 12 2015

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

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