Title

Control of polarization in bulk ferroelectrics by mechanical dislocation imprint

Publication Date

5-28-2021

Department

Ames Laboratory; Materials Science and Engineering

Campus Units

Ames Laboratory, Materials Science and Engineering

Report Number

IS-J 10535

DOI

10.1126/science.abe3810

Journal Title

Science

Volume Number

372

Issue Number

6545

First Page

961

Last Page

964

Abstract

Defects are essential to engineering the properties of functional materials ranging from semiconductors and superconductors to ferroics. Whereas point defects have been widely exploited, dislocations are commonly viewed as problematic for functional materials and not as a microstructural tool. We developed a method for mechanically imprinting dislocation networks that favorably skew the domain structure in bulk ferroelectrics and thereby tame the large switching polarization and make it available for functional harvesting. The resulting microstructure yields a strong mechanical restoring force to revert electric field–induced domain wall displacement on the macroscopic level and high pinning force on the local level. This induces a giant increase of the dielectric and electromechanical response at intermediate electric fields in barium titanate [electric field–dependent permittivity (ε33) ≈ 5800 and large-signal piezoelectric coefficient (d33*) ≈ 1890 picometers/volt]. Dislocation-based anisotropy delivers a different suite of tools with which to tailor functional materials.

Language

en

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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