Particle size effect on the microstructure and the aging process of flash-sintered barium titanate from micro and nanopowders

Abstract

Flash sintering is a novel sintering technique that allows high-density ceramics to be obtained at lowtemperatures and using short dwell times, thus providing an energy-efficient alternative to conventionalsintering. The microstructure of flash-sintered samples can be fine-tuned by a proper control ofelectrical parameters such as current density, electric field, and current profile, yielding significantimprovements of functional properties. The starting powder should also be carefully selected sincebetter sintering results are reported for smaller green grain sizes. However, this work evidences timeevolution of electrical properties of flash-sintered BaTiO₃ ceramics from submicron powders. Theresults reveal that these transformations greatly depend on powder grain size and can be furtheradjusted with an adequate selection of electric power profiles. This work provides new insights intoongoing phenomena during field-assisted sintering, such as grain growth and defect formationdynamics. Although the results focus on BaTiO3, it offers a new pathway to tailor the microstructure offlash-sintered ceramics, which may be extended to other electronic materials.