Influence of composition on the unipolar electric fatigue of Ba(Zr0.2Ti0.8)O3‐(Ba0.7Ca0.3)TiO3 lead‐free piezoceramics. Issue 10 (21st June 2017)

• Record Type: Journal Article
• Authors: Rojas, Virginia; Koruza, Jurij; Patterson, Eric A.; Acosta, Matias; Jiang, Xijie; Liu, Na; Dietz, Christian; Rödel, Jürgen
• Is Part Of: Journal of the American Ceramic Society. Volume 100:Issue 10(2017)
• Page Start: 4699
• Page End: 4709
• Publication Date: 2017-06-21
• Subjects: cyclic fatigue -- domains -- fatigue -- lead‐free ceramics -- piezoelectric materials/properties; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.15013
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: The lead‐free (1− x )Ba(Zr0.2 Ti0.8 )O3 ‐ x (Ba0.7 Ca0.3 )TiO3 system is considered as promising candidate for the replacement of lead‐based piezoceramics in actuation applications, during which electric fatigue is a major concern. This issue was addressed in this work, where the unipolar fatigue resistance of three (1− x )Ba(Zr0.2 Ti0.8 )O3 ‐ x (Ba0.7 Ca0.3 )TiO3 compositions with different crystallographic structures (rhombohedral, orthorhombic, and tetragonal) was evaluated. Strain asymmetry and development of an internal bias field were observed in all compositions. The decrease in the remanent polarization and the large signal piezoelectric coefficient after 10 7 unipolar cycles was found to lie between 6%‐12% and 2%‐13%, respectively. The most pronounced fatigue was observed for the orthorhombic composition, which has the largest extrinsic contribution to strain. On the other hand, the best fatigue resistance was observed for the tetragonal composition, which has a predominantly intrinsic strain response. The correlation of fatigue resistance with strain mechanism was corroborated with determination of the Rayleigh parameters and changes in the domain morphology after cycling as confirmed by piezoresponse force microscopy.