Manipulating Zr/Ti ratio based on phase diagram for large electrocaloric effects with multiple target operation temperatures in PLZT ceramics

Ferroelectric phase transition has been identified as a promising avenue to design high-perform electrocaloric materials for zero-emission and solid-state refrigeration. However, extensive research has been limited to developing ferroelectric materials with large electrocaloric effects near room temperature, preventing meeting the diverse refrigeration requirements. In this study, leveraging the room-temperature phase diagram of the (PbLa)(ZrTi)O₃ solution, we prepared a series of Pb_0.775La_0.15Zr_xTi_1-xO₃ bulk ceramics spanning the ferroelectric and relaxor ferroelectric phase regions. This enabled the attainment of various phase transition features and temperatures. Finally, large electrocaloric effects, coupled with adjustable operation temperatures spanning from 150 °C to -45 °C, are successfully achieved through the manipulation of the Zr/Ti ratio. This comprehensive range of operation temperatures effectively addresses the diverse refrigeration application requirements, ranging from industrial equipment to freezer cabinets. This work not only underscores the expansion of the electrocaloric refrigeration application domain but also proposes a materials design strategy tailored to meet these evolving demands.