The influences of particle sizes on the dielectric properties of PEI/(Ba0.8Sr0.2)(Ti0.9Zr0.1)O3 composites

Polyetherimide/(Ba_0.8Sr_0.2)(Ti_0.9Zr_0.1)O₃ (PEI/BSTZ) composites are fabricated using solvents, dispersant (KD1), PEI, (Ba_0.8Sr_0.2)(Ti_0.9Zr_0.1)O₃ ceramic powders. The dielectric constants of PEI/BSTZ composites with different contents and three different sizes (3 ¿m, 200 nm, and 100 nm) of BSTZ ceramic powders are measured using the plate method. The Lichtenecker logarithmic mixing rules are used to fit the measured results and predict the dielectric constants. As the content of BSTZ powders increases from 10 wt% to 70 wt%, the dielectric constants of PEI/BSTZ composites increase with the increase of BSTZ contents. When the content of BSTZ is more than 50 wt% and 100 nm and 200 nm BSTZ powders are used, the measured dielectric constants of PEI/BSTZ composites are lower than the theoretical values.