Abstract
Leveraging competition between energetically degenerate states to achieve large field-driven responses is a hallmark of functional materials, but routes to such competition are limited. Here, a new route to such effects involving domain-structure competition is demonstrated, which arises from strain-induced spontaneous partitioning of PbTiO3 thin films into nearly energetically degenerate, hierarchical domain architectures of coexisting c/a and a1/a2 domain structures. Using band-excitation piezoresponse force microscopy, this study manipulates and acoustically detects a facile interconversion of different ferroelastic variants via a two-step, three-state ferroelastic switching process (out-of-plane polarized c+ → in-plane polarized a → out-of-plane polarized c− state), which is concomitant with large nonvolatile electromechanical strains (≈1.25%) and tunability of the local piezoresponse and elastic modulus (>23%). It is further demonstrated that deterministic, nonvolatile writing/erasure of large-area patterns of this electromechanical response is possible, thus showing a new pathway to improved function and properties.
Original language | English (US) |
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Article number | 1702069 |
Journal | Advanced Materials |
Volume | 29 |
Issue number | 37 |
DOIs | |
State | Published - Oct 4 2017 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Keywords
- electromechanical responses
- ferroelectrics
- thin-film epitaxy
- three-state ferroelastic switching