Strain Mechanisms in Lead-Free Ferroelectrics for Actuators

Acosta, Matias

doi:10.1007/978-3-319-27756-1

Cited by 22 publications

(26 citation statements)

References 410 publications

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“…A series of typical ferroelectric loops of KNNS‐ x BNZS ceramics is shown in Figure A. It is easily observed from Figure B,C that the P r (remanent polarization) and E c (coercive field) values decrease with increasing BNZS content, indicating that the reversible domain structures increases in this samples . The reduction in P r and E c values can be ascribed to the low‐energy barrier in multiphase coexistence because it can lead to easy domain switching and polarization rotation …”

Section: Resultsmentioning

confidence: 93%

“…It is easily observed from Figure 5B, C that the P r (remanent polarization) and E c (coercive field) values decrease with increasing BNZS content, indicating that the reversible domain structures increases in this samples. 26 The reduction in P r and E c values can be ascribed to the low-energy barrier in multiphase coexistence because it can lead to easy domain switching and polarization rotation. 10,27 The variations in piezoelectric (d 33 , k p ) properties with composition BNZS have been displayed in Figure 6A, B.…”

Section: Resultsmentioning

confidence: 99%

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Enhanced temperature stability in the O–T phase boundary of (K, Na)NbO₃‐based ceramics

Gou

et al. 2019

J Am Ceram Soc

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In order to obtain excellent electrical properties and its temperature stability of KNN‐based ceramics to meet the practical applications, a new lead‐free material system of (1−x)K0.5Na0.5Nb0.96Sb0.04O3‐xBi0.5Na0.5Zr0.8Sn0.2O3 (KNNS‐xBNZS, 0 ≤ x ≤ 0.060) was designed, and the enhanced electrical properties (eg, d33 ~ 465 pC/N, εr ~ 3318, Suni ~ 0.133%) is obtained in the ceramics with x = 0.04. The physical origin of enhanced electric properties should be ascribed to the phase instability of R‐T, resulting in a low‐energy barrier, which can greatly facilitate the polarization switching. Moreover, the temperature stable of piezoelectric constant (d33 or d33*) is measured by three distinctive methods in different phase boundaries (O, O‐T, R‐T) at the temperature range 20°C‐180°C, revealing that the O‐T phase boundary has a relatively good temperature stability. A mode is used to show how to effectively modified the piezoelectric constant (d33 or d33*) and its temperature stability, we believe that such a strategy may further improve the temperature stability of d33 or d33* value in KNN‐based ceramics.

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Section: Resultsmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 99%

Enhanced temperature stability in the O–T phase boundary of (K, Na)NbO₃‐based ceramics

Gou

et al. 2019

J Am Ceram Soc

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“…In relaxors, the slowing down of characteristic relaxation times follows the Vogel–Fulcher law . Analysis of the characteristic relaxation times with the Vogel–Fulcher model yields a freezing temperature of 296 ± 18 K …”

Section: Resultsmentioning

confidence: 99%

Criticality: Concept to Enhance the Piezoelectric and Electrocaloric Properties of Ferroelectrics

Weyland

Acosta

Koruza

et al. 2016

Adv Funct Materials

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Compositional engineering with a focus on structural phase transitions has been considered as the most important approach for enhancement of the functional properties of ferroelectric materials due to the critical fluctuation of physical properties. Of special interest are electric‐field‐induced phase transitions, which can terminate in a liquid–vapor‐type critical point with a strong enhancement of functional properties. Whereas the critical point in liquid–vapor space considers changes in temperature and pressure, the critical point in this study is placed in electric field–temperature diagrams. In single crystals, temperature and electric field of a critical point are sharply defined and therefore not appealing for practical applications. However, in ceramics, it is demonstrated that the orientational dependence of the critical point leads to a broadened temperature and electric field range. The presence of a diffuse critical point in ceramics provides a conceptually novel approach for the enhancement of functional properties, such as piezoelectric and electrocaloric (EC) responses, as validated here on the example of the 0.75Bi1/2Na1/2TiO3‐0.25SrTiO3 lead‐free relaxor ferroelectric ceramics. The realization of a broad criticality range will further facilitate the development of the piezoelectric and EC materials and provide an alternative concept to manipulate the functional properties by application of an electric field.

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“…The authors concluded that the extrinsic contributions represent the dominant influence to the high piezoelectric response in BZT‐ x BCT. A quantification of each contribution type to the strain through small‐signal measurements as function of electric bias field was presented by Acosta et al It was revealed that extrinsic processes contribute to 54% and 64% of the total room‐temperature strain response of the rhombohedral and orthorhombic compositions, respectively. On the other hand, the highest contribution to the strain (73%) of the tetragonal 60BCT(T) sample was intrinsic in nature, which was attributed to the composition being far from any phase boundaries in the phase diagram.…”

Section: Discussionmentioning

confidence: 99%

Influence of composition on the unipolar electric fatigue of Ba(Zr_0.2Ti_0.8)O₃‐(Ba_0.7Ca_0.3)TiO₃ lead‐free piezoceramics

et al. 2017

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The lead-free (1Àx)Ba(Zr 0.2 Ti 0.8 )O 3 -x(Ba 0.7 Ca 0.3 )TiO 3 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 (1Àx)Ba (Zr 0.2 Ti 0.8 )O 3 -x(Ba 0.7 Ca 0.3 )TiO 3 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. K E Y W O R D Scyclic fatigue, domains, fatigue, lead-free ceramics, piezoelectric materials/properties

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Strain Mechanisms in Lead-Free Ferroelectrics for Actuators

Cited by 22 publications

References 410 publications

Enhanced temperature stability in the O–T phase boundary of (K, Na)NbO₃‐based ceramics

Enhanced temperature stability in the O–T phase boundary of (K, Na)NbO₃‐based ceramics

Criticality: Concept to Enhance the Piezoelectric and Electrocaloric Properties of Ferroelectrics

Influence of composition on the unipolar electric fatigue of Ba(Zr_0.2Ti_0.8)O₃‐(Ba_0.7Ca_0.3)TiO₃ lead‐free piezoceramics

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Strain Mechanisms in Lead-Free Ferroelectrics for Actuators

Cited by 22 publications

References 410 publications

Enhanced temperature stability in the O–T phase boundary of (K, Na)NbO3‐based ceramics

Enhanced temperature stability in the O–T phase boundary of (K, Na)NbO3‐based ceramics

Criticality: Concept to Enhance the Piezoelectric and Electrocaloric Properties of Ferroelectrics

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

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Product

Resources

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Enhanced temperature stability in the O–T phase boundary of (K, Na)NbO₃‐based ceramics

Enhanced temperature stability in the O–T phase boundary of (K, Na)NbO₃‐based ceramics

Influence of composition on the unipolar electric fatigue of Ba(Zr_0.2Ti_0.8)O₃‐(Ba_0.7Ca_0.3)TiO₃ lead‐free piezoceramics