Premium
High strain (0.4%) Bi(Mg 2/3 Nb 1/3 )O 3 ‐BaTiO 3 ‐BiFeO 3 lead‐free piezoelectric ceramics and multilayers
Author(s) -
Murakami Shunsuke,
Wang Dawei,
Mostaed Ali,
Khesro Amir,
Feteira Antonio,
Sinclair Derek C.,
Fan Zhongming,
Tan Xiaoli,
Reaney Ian M.
Publication year - 2018
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.15749
Subject(s) - materials science , ferroelectricity , microstructure , dielectric , phase transition , condensed matter physics , piezoelectricity , electric field , hysteresis , ceramic , analytical chemistry (journal) , piezoelectric coefficient , mineralogy , composite material , chemistry , physics , optoelectronics , chromatography , quantum mechanics
The relationship between the piezoelectric properties and the structure/microstructure for 0.05Bi(Mg 2/3 Nb 1/3 )O 3 ‐(0.95‐x)BaTiO 3 ‐ x BiFeO 3 ( BBFT , x = 0.55, 0.60, 0.63, 0.65, 0.70, and 0.75) ceramics has been investigated. Scanning electron microscopy revealed a homogeneous microstructure for x < 0.75 but there was evidence of a core‐shell cation distribution for x = 0.75 which could be suppressed in part through quenching from the sintering temperature. X‐ray diffraction ( XRD ) suggested a gradual structural transition from pseudocubic to rhombohedral for 0.63 < x < 0.70, characterized by the coexistence of phases. The temperature dependence of relative permittivity, polarization‐electric field hysteresis loops, bipolar strain‐electric field curves revealed that BBFT transformed from relaxor‐like to ferroelectric behavior with an increase in x , consistent with changes in the phase assemblage and domain structure. The largest strain was 0.41% for x = 0.63 at 10 kV /mm. The largest effective piezoelectric coefficient ( d 33 * ) was 544 pm/V for x = 0.63 at 5 kV /mm but the largest Berlincourt d 33 (148 pC /N) was obtained for x = 0.70. We propose that d 33 * is optimized at the point of crossover from relaxor to ferroelectric which facilitates a macroscopic field induced transition to a ferroelectric state but that d 33 is optimized in the ferroelectric, rhombohedral phase. Unipolar strain was measured as a function of temperature for x = 0.63 with strains of 0.30% achieved at 175°C, accompanied by a significant decrease in hysteresis with respect to room temperature measurements. The potential for BBFT compositions to be used as high strain actuators is demonstrated by the fabrication of a prototype multilayer which achieved 3 μm displacement at 150°C.