Atomically engineered interfaces yield extraordinary electrostriction

Abstract

Electrostriction is a property of all the dielectric materials where an applied electric field induces a mechanical deformation proportional to the square of the electric field. The magnitude of the effect is usually minuscule. However, recent discoveries of symmetry-breaking phenomena at interfaces opens up the possibility to extend the electrostrictive response to a broader family of dielectric materials.1,2 Here, we engineer the electrostrictive effect by epitaxially depositing alternating layers of Gd2O3-doped CeO2 and Er2O3-stabilized δ-Bi2O3 with atomically controlled interfaces on NdGaO3 substrates. We find that the electrostriction coefficient reaches 2.38×10-14 m2/V2, exceeding the best-known relaxor ferroelectrics by three orders of magnitude. Our atomic-scale calculations show that the extraordinary electrostriction coefficient is driven by the coherent strain imparted by the interfacial lattice mismatches. Thus, artificial heterostructures open a new avenue to design and manipulate electrostrictive materials and devices for nano/micro actuation and cutting-edge sensor applications.