Effect of the synthesis method and particle size on BCZT electrocaloric properties

In this study, the electrocaloric properties of BCZT ceramics fabricated through different processing methods: solid-state and sol-gel were investigated. The calcination process was done for BCZT powders obtained by sol-gel process at 900 °C for 2 h and by solid-state calcination method at 1200 °C for 6 h. BCZT-SG ceramics exhibited higher ΔT values, particularly at lower temperatures (∼0 °C–20 °C), and a stronger response to the electric field, suggesting a more efficient domain structure due to sol-gel processing. Notably, BCZT-SGH samples demonstrated the most complex and pronounced electrocaloric behavior, with dual ΔT peaks around 0 °C and 50 °C, and the highest ΔT of 2.5 K at 80 kV/cm and 50 °C, surpassing values in the literature. Especially, high ΔT results at 0 °C allows using this material in the extreme conditions. These results emphasize the significant role of processing techniques in tailoring the structural, dielectric, and electrocaloric properties of BCZT ceramics for high-performance energy applications. We believe that this article represents advancement in materials science and applied physics, and it is different from the previous studies reported in the literature on this topic. This research highlights the critical influence of synthesis methods and post-processing techniques on the dielectric, ferroelectric, and electrocaloric properties of lead-free BCZT ceramics, demonstrating that the sol-gel method combined with planetary ball milling can significantly enhance material performance, paving the way for the development of highly efficient, eco-friendly materials for advanced energy storage and solid-state cooling applications. In addition, we planned to use these materials in extreme conditions for the cooling. The study systematically compares and reports the effects of solid-state and sol-gel production methods on BCZT ceramics. It highlights the impact of high-energy milling on structural, dielectric, and electrocaloric properties. This study also establishes a systematic relationship between grain size, crystallite size, microstructural evolution, and relaxor behavior. It demonstrates improved electrocaloric efficiency (ΔT and ΔS/ΔE) in BCZT-SGH due to reduced grain size and increased relaxor behavior. The study also provides new insights into the trade-offs between dielectric constant and relaxor ferroelectric behavior caused by grain and crystallite size reduction. As a result, this study addresses critical gaps in understand