High performance relaxor ferroelectric textured ceramics for electrocaloric refrigeration

Abstract

Relaxor ferroelectric ceramics have emerged as promising candidates for electrocaloric cooling systems due to their relatively higher heating and cooling capacities. However, simultaneously achieving high temperature changes (ΔT) and a wide operating temperature range remains a significant challenge, limiting their practical applications. This work proposes a synergistic strategy that involves precise compositional tuning of the BaTiO3-xKNbO3 system to customize the rhombohedral-to-cubic phase boundary around room temperature, coupled with engineering grain orientation of the ceramics. Based on this approach, a maximum ΔT of 3.9 K is achieved in <111>c-texture BaTiO3-KNbO3 ceramics, outperforming most environmentally friendly ceramics. Notably, the ΔT variation remains within ±10% across a temperature range of 30 °C to 80 °C, demonstrating a promising material for the design and application of electrocaloric cooling devices. This work provides new insights for the design of ceramics with optimized electrocaloric properties, offering significant potential for improving the efficiency and functionality of next-generation cooling technologies and devices.