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‐
The ferroelectricity in fluorite oxides has gained increasing interest due to its promising properties for multiple applications in semiconductor as well as energy devices. The structural origin of the unexpected ferroelectricity is now believed to be the formation of a non‐centrosymmetric orthorhombic phase with the space group of
- NSF-PAR ID:
- 10063601
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Electronic Materials
- Volume:
- 4
- Issue:
- 7
- ISSN:
- 2199-160X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract 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 varyingx 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 BaTiO3lattice. 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 ofAmm2 crystal symmetry toP4mm crystal symmetry with increasingx 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 increasingx content. For (1‐x )BCZT‐(x )BCST ceramics, significantly improved dielectric and ferroelectric properties are observed, including relatively high dielectric constantε r≈ 1900–3300 (near room temperature),ε r≈ 8800–12 900 (near Curie temperature), dielectric loss, tanδ ≈ 0.01–0.02, remanent polarizationP r≈ 9.4–14 µC cm−2, coercive electric fieldE c≈ 2.5–3.6 kV cm−1. Further, high electric field‐induced strainS ≈ 0.12–0.175%, piezoelectric charge coefficientd 33≈ 296–360 pC N−1, converse piezoelectric coefficient ≈ 240–340 pm V−1, planar electromechanical coupling coefficientk p≈ 0.34–0.45, and electrostrictive coefficient (Q 33)avg≈ 0.026–0.038 m4C−2are 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. -
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