Tuning dielectric performance in novel Na1/2Er1/2Cu3Ti4O12 ceramics: The interplay of sintering temperature, grain size, and grain boundary resistance

The synthesis of novel Na1/2Er1/2Cu3Ti4O12 (NECTO) ceramics using conventional solid-state methods and their characterization as well as their dielectric properties were investigated at various temperatures of sintering. SEM results revealed an increase in average grain size with sintering temperature. The sintered NECTO sample at 1080 °C exhibited good frequency stability and a higher dielectric constant (ε′) of about 6 × 103 at 1 kHz. It is found that the sintering temperature correlates with the dielectric constant, and it agrees with the IBLC model. Additionally, the sample displayed a dielectric loss (tanδ) of less than 0.08 throughout a wide range of frequencies. Particularly, the sintered sample at 1060 °C for 10 h had a significantly low tanδ of 0.06 and exhibited a ε′ of roughly 3.19 × 103 at 1 kHz. A significant decrease in tanδ with increased Rgb was observed, suggesting that reduced grain boundary resistance could minimize the dielectric loss. Moreover, optimizing the sintering temperature enhanced the temperature stability of NECTO ceramics.