Significantly enhanced electrocaloric effect by composition modulation in lead-free BaTiO3-based ceramics

The electrocaloric effect (ECE) offers a pathway to environmentally sustainable and easily miniaturized refrigeration technology, positioning it as a front-runner for the next generation of solid-state cooling solutions. This research unveils a remarkable ECE in a finely tuned (Ba 0.86 Ca 0.14 ) 0.98 La 0.02 Ti 0.92 Sn 0.08 O 3 ceramic, exhibiting a temperature shift (Δ T ) of 1.6 K across more than 85% of the maximum Δ T (Δ T max ) and spanning an exceptionally wide operational range of 92 K. Our investigation on dielectric responses and ferroelectric polarization-electric field ( P–E ) loops suggests that the broad operational scope results from the fragmentation of extended ferroelectric domains into smaller domains and polar nano-regions (PNRs) supported by PFM analysis. Furthermore, the introduction of La enhances spontaneous polarization by significantly extending the maximum electric field that can be applied, facilitating high-performance ECE at ambient temperature. This study positions BaTiO 3 -based lead-free ceramic as a sustainable alternative for addressing the cooling demands of modern electronic components, marking a significant stride toward next-generation solid-state refrigeration.