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

Abstract

Next‐generation electronics and energy technologies can now be developed as a result of the design, discovery, and development of novel, environmental friendly lead (Pb)‐free ferroelectric materials with improved characteristics and performance. However, there have only been a few reports of such complex materials’ design with multi‐phase interfacial chemistry, which can facilitate enhanced properties and performance. In this context, herein, novel lead‐free piezoelectric materials (1‐x)Ba0.95Ca0.05Ti0.95Zr0.05O3‐(x)Ba0.95Ca0.05Ti0.95Sn0.05O3, are reported, which are represented as (1‐x)BCZT‐(x)BCST, with demonstrated excellent properties and energy harvesting performance. The (1‐x)BCZT‐(x)BCST materials are synthesized by high‐temperature solid‐state ceramic reaction method by varying x in the full range (x = 0.00–1.00). In‐depth exploration research is performed on the structural, dielectric, ferroelectric, and electro‐mechanical properties of (1‐x)BCZT‐(x)BCST ceramics. The formation of perovskite structure for all ceramics without the presence of any impurity phases is confirmed by X‐ray diffraction (XRD) analyses, which also reveals that the Ca2+, Zr4+, and Sn4+ are well dispersed within the BaTiO3 lattice. For all (1‐x)BCZT‐(x)BCST ceramics, thorough investigation of phase formation and phase‐stability using XRD, Rietveld refinement, Raman spectroscopy, high‐resolution transmission electron microscopy (HRTEM), and temperature‐dependent dielectric measurements provide conclusive evidence for the coexistence of orthorhombic + tetragonal (Amm2 + P4mm) phases at room temperature. The steady transition of Amm2 crystal symmetry to P4mm crystal symmetry with increasing x content is also demonstrated by Rietveld refinement data and related analyses. The phase transition temperatures, rhombohedral‐orthorhombic (TR‐O), orthorhombic‐ tetragonal (TO‐T), and tetragonal‐cubic (TC), gradually shift toward lower temperature with increasing x content. For (1‐x)BCZT‐(x)BCST ceramics, significantly improved dielectric and ferroelectric properties are observed, including relatively high dielectric constant εr ≈ 1900–3300 (near room temperature), εr ≈ 8800–12 900 (near Curie temperature), dielectric loss, tan δ ≈ 0.01–0.02, remanent polarization Pr ≈ 9.4–14 µC cm−2, coercive electric field Ec ≈ 2.5–3.6 kV cm−1. Further, high electric field‐induced strain S ≈ 0.12–0.175%, piezoelectric charge coefficient d33 ≈ 296–360 pC N−1, converse piezoelectric coefficient ≈ 240–340 pm V−1, planar electromechanical coupling coefficient kp ≈ 0.34–0.45, and electrostrictive coefficient (Q33)avg ≈ 0.026–0.038 m4 C−2 are attained. Output performance with respect to mechanical energy demonstrates that the (0.6)BCZT‐(0.4)BCST composition (x = 0.4) displays better efficiency for generating electrical energy and, thus, the synthesized lead‐free piezoelectric (1‐x)BCZT‐(x)BCST samples are suitable for energy harvesting applications. The results and analyses point to the outcome that the (1‐x)BCZT‐(x)BCST ceramics as a potentially strong contender within the family of Pb‐free piezoelectric materials for future electronics and energy harvesting device technologies.

One-Step Synthesis and Operando Electrochemical Impedance Spectroscopic Characterization of Heterostructured MoP–Mo2N Electrocatalysts for Stable Hydrogen Evolution Reaction

“…The EDS elemental mapping analyses from the hierarchies are shown in Figure f–i. The EDS spectra and mapping analyses can validate the chemical homogeneity and elemental composition since the X-ray energy is a property of the specific atom(s) that is/are involved in the generation of the X-rays. , Thus, the presence of both P and N along with Mo suggests contribution of both MoP and Mo 2 N phases in the formed hierarchies. The phase modulation of the complex material with multiple anions may also involve interfacial stress, which may also be beneficial to enhance the electrochemical property.…”

Chemical-Composition Tuning-Enabled Optimization of Structure, Properties, and Performance of Lead-Free (1 – x)BaZr0.05Ti0.95O3–(x)Ba0.92Ca0.08TiO3 Electroceramics

“…Toward realization of Pb-free ferroelectrics, BaTiO 3 (BT)-based compounds can play a vital role. , However, in comparison to Pb-based materials such as PZT, the lead-free piezoelectric materials (as BaTiO 3 ) exhibit poor properties, viz., lower piezoelectric coefficient ( d 33 < 200 pC/N), lower Curie temperature, and higher dielectric loss. Recently, there have been a few successful attempts that made the realization of novel Pb-free materials possible for higher piezoelectric response, d 33 = 300 to 600 pC/N. , In one of these attempts, Liu and Ren have prepared a morphotropic phase boundary (MPB) composition BaZr 0.20 Ti 0.80 O 3 –0.5Ba 0.70 Ca 0.30 TiO 3 (abbreviated as BZT–BCT) and reported the piezoelectric coefficient ( d 33 ∼ 620 pC/N), which is the highest among the known lead-free and environmentally friendly materials. , This report fascinated the scientific community to further explore BT-based lead-free materials with reduced environmental concerns …”

Pr-Doped Inorganic SrCeO3 Perovskite Nanophosphors as Activated Compact Layers for (CH3NH3)2CuBr4 Perovskite Solar Cells

“…Generally, perovskites are structured as an ABX 3 general formula; these structures provide considerable flexibility and have a wide range of applications in various optoelectronic devices such as photodetectors, , solar cells, lasers, electrocatalytic activity, piezoelectrics, and light-emitting diodes (LEDs). − Among perovskites, lead-based PSCs are the most efficient and have been widely explored for commercialization . However, its toxicity and high environmental sensitivity are major challenges, limiting a wide range of practical applications of Pb.…”