Assessment of the functional properties stability in (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 piezoceramics: Huge dielectric and piezoelectric nonlinearity

Abstract

The (Ba,Ca)(Zr,Ti)O3 ceramic system has received special attention in recent years because it may lead to promising lead-free piezoceramics. However, the stability of the functional properties of these materials is an important issue that requires greater attention. In this work, the (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 compound (BCZT) is taken as a reference material for evaluating the variation of the functional properties when an external stimulus (e.g., electric field or dynamical stress) is applied, which may constitute an important drawback of piezoceramics. The results show that BCZT exhibits a huge nonlinear behavior, which notably limits this leadfree material for transfer to applications. The instabilities manifest at considerably low amplitudes of the applied electric field or dynamical stress due to a large extrinsic contribution from the irreversible motion of domain walls. Understanding and controlling the physical phenomena related to the domain wall motion presents a fundamental challenge for achieving an effective enhancement of the functional property stability of this system.

Confocal Raman Microscopy, Synchrotron X-ray Diffraction, and Photoacoustic Study of Ba0.85Ca0.15Ti0.90Zr0.10O3: Understanding Structural and Microstructural Response to the Electric Field

“…The described texture evolution reveals a high degree of ferroelectric−ferroelastic domain orientation under the electric field. 33 The high mobility of domain walls needed to produce this texture is most likely the origin of the huge extrinsic contribution to the electromechanical activity of BCTZ ceramics (67% 12 ) of this weakly distorted perovskite structure (Table 1).…”

“…In particular, the structural and microstructural evolution produced employing an external electric field application is a key parameter to understanding the effect over the intrinsic response of the material. BCTZ features a multiphase coexisting point or triple point (TCP), ,, in which it is currently considered that both the intrinsic contribution, related to the field-induced lattice distortion (polarization rotation and extension), and the extrinsic contributions, related to the non-180° domain wall mobility, maximize . This tricritical point, first reported in 2009, of the coexistence near room temperature of the paraelectric (PE-cubic) and two ferroelectric (FE-tetragonal and FE-rhombohedral) phases was amended in 2014 by a compositional study of the (1 – x )­Ba­(Zr 0.2 Ti 0.8 )­O 3 – x (Ba 0.7 Ca 0.3 )­TiO 3 (BZT-BCT) system by means of dielectric permittivity, small signal d 33 and large signal d 33 * properties measured as functions of temperature.…”

“…BCTZ features a multiphase coexisting point or triple point (TCP), 8,9,11 in which it is currently considered that both the intrinsic contribution, related to the field-induced lattice distortion (polarization rotation and extension), and the extrinsic contributions, related to the non-180°domain wall mobility, maximize. 12 This tricritical point, first reported in 2009, 9 of the coexistence near room temperature of the paraelectric (PE-cubic) and two ferroelectric (FE-tetragonal and FE-rhombohedral) phases was amended in 2014 13 by a compositional study of the (1 − x)Ba(Zr 0.2 Ti 0.8 )O 3 −x(Ba 0.7 Ca 0.3 )TiO 3 (BZT-BCT) system by means of dielectric permittivity, small signal d 33 and large signal d 33 * properties measured as functions of temperature. This study determined a "convergence region", after a previous analysis on synchrotron X-ray diffraction 14 characterized by a small noncubic distortion that was associated with a FEorthorhombic phase, in which FE−FE boundaries maximizes the electromechanical properties.…”

Enhanced Piezoelectric, Ferroelectric, and Electrostrictive Properties of Lead‐Free (1‐x)BCZT‐(x)BCST Electroceramics with Energy Harvesting Capability

“…[1][2][3][4][5][6][7] It is well known that lead (Pb) based materials, such as Pb(Zr,Ti)O 3 (PZT) and Pb(Mg 1/3 Nb 2/3 )-PbTiO 3 (PMN-PT), are the most commonly utilized piezoelectric materials with excellent piezoelectric properties (piezoelectric coefficient d 33 ≈580 pC N −1 ), presence of morphotropic phase boundary, and higher working temperatures. [2][3][4][5][6][7][8][9][10][11][12] However, these harmful Pb-based piezoelectric ceramics, which contain ≈60 wt% of Pb and are toxic, contribute to environmental contamination and pose a risk to human health. In this connection, European Union legislation (RoHS; Directive 2002/95/EC & Directive 2011/65/EU) [13] placed limitations/restrictions on the use of Pb-based materials which stimulates the scientific and engineering community to search for high-performance, eco-friendly, and Pb-free piezoelectric materials.…”

“…In this connection, European Union legislation (RoHS; Directive 2002/95/EC & Directive 2011/65/EU) [13] placed limitations/restrictions on the use of Pb-based materials which stimulates the scientific and engineering community to search for high-performance, eco-friendly, and Pb-free piezoelectric materials. [2][3][4][5][6][7][8][9][10][11][12] The restrictions have forced the replacement of Pb-use in a number of technological applications. Unfortunately, the suitable Pb-free substitutes are still not readily available at this time.…”