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Enhanced electrocaloric effect over a broad temperature range in lead‐free Na0.5Bi0.5TiO3‐based relaxor ferroelectrics via doping with Bi(Mg0.5Zr0.5)O3
- Source :
- IET Nanodielectrics, Vol 7, Iss 2, Pp 59-67 (2024)
- Publication Year :
- 2024
- Publisher :
- Wiley, 2024.
-
Abstract
- Abstract With an increasing demand for environmentally friendly refrigeration, the solid‐state refrigeration based on the electrocaloric effect (ECE) has been drawn extensive attention. It is a challenge to maintain a large adiabatic temperature change (∆T) over a broad temperature span. Herein, the authors designed and synthesised (0.74‐x) Na0.5Bi0.5TiO3‐0.06BaTiO3‐0.2SrTiO3‐xBi(Mg0.5Zr0.5)O3 (abbreviated as NBT‐xBMZ) (x = 0, 0.02, 0.04, 0.06 and 0.08) lead‐free relaxor ferroelectrics. Their microstructures, dielectric properties, ferroelectric properties, ECEs and the structure‐property relationships were investigated. Via doping with BMZ, an enhanced relaxor feature and a wider temperature range where multi‐phases coexist were achieved. The relaxor ferroelectric characteristics were illustrated using the Vogel‐Fulcher relation. The indirectly calculated ECE results showed that the optimal ΔT of 1.11 K was obtained for the x = 0.02 sample at 90°C and 70 kV/cm over a wide Tspan of 120°C, providing a potential ECE material. The direct ECE results procured using thermocouple indicated that the maximal ∆T of 2.14 K and ∆T/∆E of 0.31 K m/MV were achieved in the same sample at 70°C and 7 MV/m and the variation trend of ECE results was consistent with the indirect results. Moreover, the multi‐phases coexistent strategy can be extended to other materials system to generate a large ΔT over a wide temperature range.
Details
- Language :
- English
- ISSN :
- 25143255
- Volume :
- 7
- Issue :
- 2
- Database :
- Directory of Open Access Journals
- Journal :
- IET Nanodielectrics
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.9838d44aecf24fc19f1ae508363d5fcd
- Document Type :
- article
- Full Text :
- https://doi.org/10.1049/nde2.12069