Recent developments in ferroelectric relaxor ceramics: Implications for high-temperature capacitive dielectrics

Dielectric capacitors that maximize recoverable energy density, charge-discharge, and thermal performance withstand intense heat and vibration while minimizing size and weight; however, lead-free materials are constrained by the compromise between the energy storage density and efficiency and the breakdown charge and current. We overview recent developments in relaxor ferroelectric (RFE) and antiferroelectric (AFE) ceramics, focusing on systems with lead-free candidates and the microstructural rules that govern energy storage. By holistically combining the lessons learned across bulk and thin-film devices, this review offers a guide to adapting laboratory success in lead-free relaxor dielectrics to high-temperature, high-power applications in vehicles, aerospace and defense systems.