Giant intrinsic electrocaloric effect in ferroelectrics by local structural engineering

• Published in: Nature communications Vol. 16; no. 1; pp. 7515 - 10
• Main Authors: Wu, Bo, Tao, Hong, Chen, Kui, Xing, Zhipeng, Wu, Yan-Qi, Thong, Hao-Cheng, Zhao, Lin, Zhao, Chunlin, Xu, Ze, Liu, Yi-Xuan, Yao, Fang-Zhou, Zhou, Tianhang, Ma, Jian, Wei, Yan, Wang, Ke, Zhang, Shujun
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.08.2025; Nature Publishing Group; Nature Portfolio
• Subjects: 140/133; 140/146; 147/137; 639/301/1005/1007; 639/301/299/2736; Barium; Barium titanates; Cations; Ceramics; Cooling; Curie temperature; Design; Dielectric constant; Dielectric properties; Dipoles; Electric fields; Energy; Ferroelectric materials; Ferroelectricity; Ferroelectrics; Humanities and Social Sciences; multidisciplinary; Phase transitions; Polarization; Refrigeration; Room temperature; Rotation; Science; Science (multidisciplinary); Structural design; Structural engineering; Vapor compression refrigeration
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-025-61860-5

The electrocaloric effect of ferroelectrics holds great promise for solid-state cooling, potentially replacing traditional vapor-compression refrigeration systems. However, achieving adequate electrocaloric cooling capacity at room temperature remains a formidable challenge due to the need for a high intrinsic electrocaloric effect. While barium titanate ceramic exhibits a pronounced electrocaloric effect near its Curie temperature, typical chemical modifications to enhance electrocaloric properties at room temperature often reduce this intrinsic electrocaloric effect. Herein, a structural design is introduced for barium titanate-based ceramics by incorporating isovalent cations. This leads to a well-ordered local structure that decreases the Curie temperature to room temperature while preserving a sharp phase transition, enabling a large dielectric constant and tunable polarization. This design achieves a remarkable electrocaloric strength of ~1.0 K·mm/kV, surpassing previous reports. Atomic-resolution structural analyses reveal that the presence of multiscale nanodomains (from ~10 nm to >100 nm), and the dipole polarization distribution with gradual dipole rotation enable rapid phase transition and facile polarization rotation, accounting for the giant electrocaloric response. This work provides a strategy for achieving a strong intrinsic electrocaloric effect in ferroelectrics near room temperature and offers key insights into the microstructure landscapes driving this enhanced electrocaloric effect. The authors introduce a structural design with a well-ordered local structure for barium titanate-based ceramics, which decreases Curie temperature while preserves a sharp phase transition, enabling tunable polarization, large dielectric constant and intrinsic electrocaloric effect near room temperature.