1. Polar Vortices in Relaxor Ferroelectric Ceramics for High-Efficiency Capacitive Energy Storage.
- Author
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Chen F, Chen M, Zhang J, Liu W, Du H, Zong Q, Yu H, Zhang Y, Hao J, Wang J, and Zhai J
- Abstract
Polar vortices are predominantly observed within the confined ferroelectric films and the ferroelectric/paraelectric superlattices. This raises the intriguing question of whether polar vortices can form within relaxor ferroelectric ceramics and subsequently contribute to their energy storage performances. Here, we incorporate 10 mol % CaSnO
3 into the 0.7NaNbO3 -0.3Sr0.7 Bi0.2 TiO3 matrix, yielding a coexistence of phases: 48.8% orthorhombic P 21 / ma , 49.1% tetragonal P 4 bm , and 2.1% tetragonal P 42 / mnm SnO2 , which is confirmed by the combination of X-ray diffraction and transmission electron microscopy. The ceramic features a pronounced core-shell structure with the shell region rich in stripe nanoscale domains of the P 21 / ma phase and the core region consisting of polar nanoregions deficient in the P 21 / ma phase, forming polar vortices. Consequently, the ceramic achieves an impressive recoverable energy storage density of 6.83 J cm-3 and an exceptional efficiency of 95.7% at a high breakdown strength of 750 kV cm-1 , along with superior stability in frequency, temperature, and cycling. These results not only offer a viable approach for developing high-performance energy storage ceramics through the controlled formation of polar vortices but also offer the potential for direct electric-field control of polar vortices for high-speed data processing and storage.- Published
- 2025
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