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The Composition and Temperature‐Dependent Structure Evolution and Large Strain Response in (1− x )( Bi 0.5 Na 0.5 ) TiO 3 − x Ba ( Al 0.5 Ta 0.5 ) O 3 Ceramics
Author(s) -
Bai Wangfeng,
Bian Yanlong,
Hao Jigong,
Shen Bo,
Zhai Jiwei
Publication year - 2013
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.12039
Subject(s) - materials science , raman spectroscopy , ferroelectricity , polarization (electrochemistry) , piezoelectricity , dielectric , strain (injury) , depolarization , analytical chemistry (journal) , thermal expansion , pyroelectricity , monoclinic crystal system , mineralogy , crystallography , composite material , chemistry , crystal structure , optics , physics , medicine , optoelectronics , chromatography , endocrinology
The (1− x ) ( Bi 0.5 Na 0.5 ) TiO 3 − x Ba ( Al 0.5 Ta 0.5 ) O 3 ((1− x ) BNT ‐ x BAT ) lead‐free piezoceramics was fabricated using a conventional solid‐state reaction method. The temperature and composition‐dependent strain behavior, dielectric, ferroelectric (FE), piezoelectric, and pyroelectric properties have been systematically investigated to develop lead‐free piezoelectric materials with large strain response for actuator application. As the BAT content increased, the FE order is disrupted resulting in a degradation of the remanent polarization, coercive field, and the depolarization temperature ( T d ). A large strain of 0.36% with normalized strain d 33 * = 448pm/V was obtained for the optimum composition x = 0.045 at room temperature. The bipolar and unipolar strains for the compositions x = 0.035 and x = 0.04 reach almost identical maximum values when the temperature is in the vicinity of their respective depolarization temperature ( T d ). The Raman‐spectra analysis, macroscopic properties, thermal depolarization results, and temperature‐dependent relationships of both polarization and strain demonstrated that the origin of the large strain response for this investigated system is attributed to a field‐induced relaxor to FE phase transformation.