Induced giant piezoelectricity in centrosymmetric oxides

Piezoelectrics are materials that linearly deform in response to an applied electric field. As a fundamental prerequisite, piezoelectric materials must have a noncentrosymmetric crystal structure. For more than a century, this has remained a major obstacle for finding piezoelectric materials. We circumvented this limitation by breaking the crystallographic symmetry and inducing large and sustainable piezoelectric effects in centrosymmetric materials by the electric field-induced rearrangement of oxygen vacancies. Our results show the generation of extraordinarily large piezoelectric responses [with piezoelectric strain coefficients (d(33)) of similar to 200,000 picometers per volt at millihertz frequencies] in cubic fluorite gadolinium-doped CeO2-x films, which are two orders of magnitude larger than the responses observed in the presently best-known lead-based piezoelectric relaxor-ferroelectric oxide at kilohertz frequencies. These findings provide opportunities to design piezoelectric materials from environmentally friendly centrosymmetric ones.

Automated summary

This study breaks the crystallographic symmetry and induces large and sustainable piezoelectric effects in centrosymmetric materials. The experiment shows the generation of extraordinarily large piezoelectric responses in cubic fluorite gadolinium-doped CeO2-x films, which are two orders of magnitude larger than the responses observed in the presently best-known lead-based piezoelectric relaxor-ferroelectric oxide. This finding provides opportunities to design environmentally friendly piezoelectric materials.