title: Piezoelectric enhancement under negative pressure.
abstract: Enhancement of ferroelectric properties, both spontaneous polarization and Curie temperature under negative pressure had been predicted in the past from first principles and recently confirmed experimentally. In contrast, piezoelectric properties are expected to increase by positive pressure, through polarization rotation. Here we investigate the piezoelectric response of the classical PbTiO3, Pb(Zr,Ti)O3 and BaTiO3 perovskite ferroelectrics under negative pressure from first principles and find significant enhancement. Piezoelectric response is then tested experimentally on free-standing PbTiO3 and Pb(Zr,Ti)O3 nanowires under self-sustained negative pressure, confirming the theoretical prediction. Numerical simulations verify that negative pressure in nanowires is the origin of the enhanced electromechanical properties. The results may be useful in the development of highly performing piezoelectrics, including lead-free ones.
authors.affiliation: Ceramics Laboratory, Swiss Federal Institute of Technology (EPFL), 1015 Lausanne, Switzerland.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kvasov
authors.affiliation: Ceramics Laboratory, Swiss Federal Institute of Technology (EPFL), 1015 Lausanne, Switzerland.
authors.forename: Leo J
authors.initials: LJ
authors.lastname: McGilly
authors.affiliation: Division of Energy and Environment, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.affiliation: Division of Energy and Environment, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Ceramics Laboratory, Swiss Federal Institute of Technology (EPFL), 1015 Lausanne, Switzerland.|3D-OXIDES, 70 rue Gustave Eiffel, 01630 Saint Genis Pouilly, France.
authors.forename: Cosmin S
authors.initials: CS
authors.lastname: Sandu
authors.affiliation: Ceramics Laboratory, Swiss Federal Institute of Technology (EPFL), 1015 Lausanne, Switzerland.
authors.forename: Tomas
authors.initials: T
authors.lastname: Sluka
authors.affiliation: Ceramics Laboratory, Swiss Federal Institute of Technology (EPFL), 1015 Lausanne, Switzerland.
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Tagantsev
authors.affiliation: Ceramics Laboratory, Swiss Federal Institute of Technology (EPFL), 1015 Lausanne, Switzerland.
authors.forename: Nava
authors.initials: N
authors.lastname: Setter