title: Dual strain mechanisms in a lead-free morphotropic phase boundary ferroelectric.
abstract: Electromechanical properties such as d33 and strain are significantly enhanced at morphotropic phase boundaries (MPBs) between two or more different crystal structures. Many actuators, sensors and MEMS devices are therefore systems with MPBs, usually between polar phases in lead (Pb)-based ferroelectric ceramics. In the search for Pb-free alternatives, systems with MPBs between polar and non-polar phases have recently been theorized as having great promise. While such an MPB was identified in rare-earth (RE) modified bismuth ferrite (BFO) thin films, synthesis challenges have prevented its realization in ceramics. Overcoming these, we demonstrate a comparable electromechanical response to Pb-based materials at the polar-to-non-polar MPB in Sm modified BFO. This arises from 'dual' strain mechanisms: ferroelectric/ferroelastic switching and a previously unreported electric-field induced transition of an anti-polar intermediate phase. We show that intermediate phases play an important role in the macroscopic strain response, and may have potential to enhance electromechanical properties at polar-to-non-polar MPBs.
authors.affiliation: Electronic Ceramics Department, Jozef Stefan Institute, Ljubljana, Slovenia.|The School of Materials Science and Engineering, University of New South Wales, Sydney, Australia.
authors.forename: Julian
authors.initials: J
authors.lastname: Walker
authors.affiliation: Department of Physics, Technical University of Denmark, Lyngby DK-2800 kgs. Denmark.
authors.forename: Hugh
authors.initials: H
authors.lastname: Simons
authors.affiliation: Nanofer Laboratory, Institute of Natural Sciences, Ural Federal University, Ekaterinburg, Russia.
authors.forename: Denis O
authors.initials: DO
authors.lastname: Alikin
authors.affiliation: Nanofer Laboratory, Institute of Natural Sciences, Ural Federal University, Ekaterinburg, Russia.
authors.forename: Anton P
authors.initials: AP
authors.lastname: Turygin
authors.affiliation: Nanofer Laboratory, Institute of Natural Sciences, Ural Federal University, Ekaterinburg, Russia.
authors.forename: Vladimir Y
authors.initials: VY
authors.lastname: Shur
authors.affiliation: Nanofer Laboratory, Institute of Natural Sciences, Ural Federal University, Ekaterinburg, Russia.|CICECO &Department of Materials and Ceramics Engineering, University of Aveiro, Aveiro, Portugal.
authors.forename: Andrei L
authors.initials: AL
authors.lastname: Kholkin
authors.affiliation: Electronic Ceramics Department, Jozef Stefan Institute, Ljubljana, Slovenia.
authors.forename: Hana
authors.initials: H
authors.lastname: Ursic
authors.affiliation: Electronic Ceramics Department, Jozef Stefan Institute, Ljubljana, Slovenia.
authors.forename: Andreja
authors.initials: A
authors.lastname: Bencan
authors.affiliation: Electronic Ceramics Department, Jozef Stefan Institute, Ljubljana, Slovenia.
authors.forename: Barbara
authors.initials: B
authors.lastname: Malic
authors.affiliation: The School of Materials Science and Engineering, University of New South Wales, Sydney, Australia.
authors.forename: Valanoor
authors.initials: V
authors.lastname: Nagarajan
authors.affiliation: Electronic Ceramics Department, Jozef Stefan Institute, Ljubljana, Slovenia.
authors.forename: Tadej
authors.initials: T
authors.lastname: Rojac