Enhanced densification and dielectric properties of BaTiO3 through a cold-sintering pre-treatment

The cold sintering process (CSP) is utilized as a pre-treatment to densify BaTiO₃ before subsequent conventional sintering (TS). A comparison between two different processing routes, with or without the CSP pre-treatment (CSP + TS or TS). After CSP at 225 °C and subsequent TS at 1000 °C, a high relative density (e.g., 96.86 % TD) was obtained with an average grain size of 1.52 μm, while corresponding outcomes of 60.56 % TD and 0.29 μm were obtained in the sample without the CSP pre-treatment. This dramatic improvement was evident in a wide temperature range from 900 to 1200 °C, leading to superior dielectric properties to the TS samples in a frequency range from 1 kHz to 1 MHz. The enhanced performance is attributable to reduced secondary phases, an enhanced relative density, and the optimal grain size realized by modifying the processing temperatures, highlighting the benefits of the CSP pre-treatment.