Epitaxial PbZrxTi1−xO3 Ferroelectric Bilayers with Giant Electromechanical Properties. Issue 8 (20th April 2015)

• Record Type: Journal Article
• Authors: Huang, Hsin‐Hui; Zhang, Qi; Huang, Esther; Maran, Ronald; Sakata, Osami; Ehara, Yoshitaka; Shiraishi, Takahisa; Funakubo, Hiroshi; Munroe, Paul; Valanoor, Nagarajan
• Is Part Of: Advanced materials interfaces. Volume 2:Issue 8(2015)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2015-04-20
• Subjects: electromechanical coefficients -- ferroelastic domain engineering -- ferroelectric thin films; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.201500075
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract : Giant electromechanical response viaferroelastic domain switching is achieved in epitaxial (001) ferroelectric tetragonal (T) PbZr0.3 Ti0.7 O3 /rhombohedral (R) PbZr0.55 Ti0.45 O3 bilayers, grown on La0.67 Sr0.33 MnO3 buffered SrTiO3 substrates. X‐ray diffraction and transmission electron microscopy show that the domain structure of the T films is tuned as a function of its thickness, from a fully a1 /a2 ‐domains (30 nm thick T layer) to a three domain stress‐free c/a1 /c/a2 polytwin state (100 nm thick T layer). A large switchable polarization is found up to 65 μC cm −2 . Quantitative piezoelectric force microscopy reveals enhanced piezoelectric coefficients, with d33 coefficients ranging from 250 to 350 pm V −1, which is up to seven times higher than the nominal PbZrx Ti1−x O3 thin film values. These are attributed to the motion of nanoscale ferroelastic domains. Fatigue testing proves that these domains are reversible and repeatable up to 10 7 cycles. In‐situ X‐ray synchrotron measurements reveal that the ferroelastic domain switching is promoted by a pulsating strain effect imposed by the R layer. The study reports a fundamental understanding of the origin of giant piezoelectric coefficients in epitaxial ferroelectric bilayers. Abstract : Giant electromechanical response via ferroelastic domain switching is achieved in epitaxial (001) ferroelectric tetragonal (T) PbZr0.30 Ti0.70 O3 /rhombohedral (R) PbZr0.55 Ti0.45 O3 bilayers, grown on La0.67 Sr0.33 MnO3 buffered SrTiO3 substrates. A fivefold increase in the observed d 33 coefficient is attributed to the motion of nanoscale ferroelastic domains.