Improvement of temperature-stable BaTiO3-based dielectrics by addition of Li2CO3 and Co2O3

The influence of Co2O3 and Li2CO3 on the dielectric constant-temperature characteristic of the BaTiO3–Nb2O5–La2O3–Sm2O3 system (BNLS) was studied. The Co element is useful to flatten the dielectric constant-temperature curve at low temperature. Compared with the influence of Co2O3, Li2CO3 is an effective additive that can improve the dielectric constant of this system at high temperature near the Curie temperature. This is very helpful for this ceramic system to satisfy the requirement of EIA X7R specification on TCC and still keep a relatively high dielectric constant at room temperature. The possible mechanism of the phenomenon was also discussed.