Review: cold sintering-driven structural and dielectric–ferroelectric development in complex oxides

Cold sintering has emerged as a transformative low-temperature densification strategy for fabricating high-performance ABO₃-type complex metal oxides, offering a sustainable alternative to conventional high-temperature ceramic processing. This review consolidates recent advances in cold-sintered electroceramics, including Sr 0.7 Bi 0.2 TiO 3 , BaTiO 3 , Pb(Zr, Ti)O 3 , BaTiO 3 –CaTiO 3 :Pr 3+ , and (Bi 0.5 Na 0.5 ) 0.94 Ba 0.06 TiO 3, highlighting how pressure-assisted transient-liquid densification enables refined grain structures, reduced porosity, and enhanced dielectric–ferroelectric performance. The cold sintering is considered to be the energy-efficient technique enabling dense microstructures at temperatures as low as 180 °C. Across diverse synthesis routes, including solid-state, hydrothermal, sol-gel, and tape-casting, cold sintering consistently promotes nanoscale grain formation, suppresses volatilization, and improves phase purity. These microstructural advantages translate into superior electrical responses, such as increased breakdown strength, stable relaxor behavior, and improved energy-storage characteristics. Remaining challenges include precursor solubility limits, secondary-phase formation, and the need for deeper mechanistic understanding under high-pressure conditions. Overall, this review underscores cold sintering’s growing potential to reshape the processing landscape for next-generation dielectric and ferroelectric oxides.