Broad temperature span and large electrocaloric effect in lead-free ceramics via multi-strategy synergistic optimization

The rapid advancement of electronic technology has increased power consumption in integrated circuits, presenting significant challenges for efficient cooling. BaTiO₃ (BT)-based ceramics offer promising electrocaloric (EC) cooling, providing a compact, efficient alternative to bulky, environmentally harmful vapor compression refrigeration, though temperature span (T_span) and phase transitions limit their current practicality. This study explores a novel (0.5-x)Ba_0.72Sr_0.28TiO₃-0.5BaTi_0.8Sn_0.2O₃-xBa_0.72Ca_0.28TiO₃ [(0.5-x)BST-BTS-xBCT] ceramic system, leveraging phase boundary engineering to achieve continuous and broad phase transitions. By optimizing grain size and enhancing the breakdown electric field (E_b) through a density adjustment strategy, the 0.2BCT ceramics demonstrated excellent EC performance at 38 °C, with a ΔT of 2.71 K and a T_span of 49.1 °C. These findings establish (0.5-x)BST-BTS-xBCT ceramics as a promising lead-free material for EC applications with significant potential for improving microelectronic cooling solutions.