resumo
Electromechanical properties such as d(33) 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.
palavras-chave
FIELD-INDUCED STRAIN; FREE PIEZOCERAMICS; BIFEO3 CERAMICS; ELECTROMECHANICAL RESPONSE; PIEZOELECTRIC PROPERTIES; TITANATE CERAMICS; BISMUTH FERRITE; THIN-FILMS; TRANSITION; BEHAVIOR
categoria
Science & Technology - Other Topics
autores
Walker, J; Simons, H; Alikin, DO; Turygin, AP; Shur, VY; Kholkin, AL; Ursic, H; Bencan, A; Malic, B; Nagarajan, V; Rojac, T
nossos autores
Andrei Kholkin
Investigador Principalagradecimentos
This work was jointly funded by Slovenian Research Agency program