Ultrahigh piezoelectricity in ferroelectric ceramics by design

Abstract

Piezoelectric materials, which respond mechanically to applied electric field and vice versa, are essential for electromechanical transducers. Previous theoretical analyses have shown that high piezoelectricity in perovskite oxides is associated with a flat thermodynamic energy landscape connecting two or more ferroelectric phases. Here, guided by phenomenological theories and phase-field simulations, we propose an alternative design strategy to commonly used morphotropic phase boundaries to further flatten the energy landscape, by judiciously introducing local structural heterogeneity to manipulate interfacial energies (that is, extra interaction energies, such as electrostatic and elastic energies associated with the interfaces). To validate this, we synthesize rare-earth-doped Pb(MgNb)O-PbTiO (PMN-PT), as rare-earth dopants tend to change the local structure of Pb-based perovskite ferroelectrics. We achieve ultrahigh piezoelectric coefficients d of up to 1,500 pC N and dielectric permittivity ε/ε above 13,000 in a Sm-doped PMN-PT ceramic with a Curie temperature of 89 °C. Our research provides a new paradigm for designing material properties through engineering local structural heterogeneity, expected to benefit a wide range of functional materials.

Temperature‐insensitive piezoelectricity in lead‐free NaNbO3‐based ceramics

“…Figure (A) exhibits the turning point of each composition, from which S uni starts to decrease sharply. The variation in S uni in the ceramic with x = 0.03 is also observed in KNN‐based ceramics that have a PPB and an enhanced temperature stability, whereas the ceramics with x = 0.035‐0.04 exhibit similar variations of S uni to those of 2.5Sm‐PMN‐31PT ceramics that have an MPB, further manifesting the character of the MPB‐like at x = 0.035‐0.04.…”

“…More importantly, these ceramics x = 0‐0.03 display a stable ε r from 20°C to a temperature below their T c (Figure A‐E), which is responsible for the variation in d 33 values . However, at x = 0.035‐0.04, an MPB‐like is observed, which accounts for the stable d 33 values below their T c . Then, the temperature stability concerning in situ d 33 values of several representative lead‐free ceramics are compared in Figure (D).…”

Scaling behavior of dynamic hysteresis of PMN‐PT relaxor ferroelectric ceramics near the morphotropic phase boundary

“…The most common feature of ferroelectric is the existence of domains that can be switched from one direction to another one with an applied electric field . Compared with single crystals, the preparation processes of relaxor PMN‐PT ceramics are simpler and more economical.…”

Reversible luminescence modulation and temperature‐sensing properties of Pr3+/Yb3+ codoped K0.5Na0.5NbO3 ceramics

“…Recently, composition‐modified KNN ceramics have being considered to be a promising candidate to replace conventional lead zirconate titanate (PZT) ferroelectric materials . What is more important, it has been revealed that the ferroelectric ceramics doped with RE ions show a dramatically enhanced electrical property because of the introduced local structure heterogeneity, besides their unique luminescent behaviors . In addition, the UC luminescence can be effectively modulated via a photochromic (PC) reaction in the KNN ceramics .…”