Abstract: The doping effects of NiNb₂O₆, CaZrO₃ and MnCO₃ on the dielectric properties and breakdown voltages of fine grain BaTiO₃ systems were studied. NiNb₂O₆ can shift the Curie temperature and broaden it, and makes contributions to double peaks; CaZrO₃ may improve the temperature coefficiency characteristic greatly and enhance the withstand voltage; adding MnCO₃ can restrain the overgrowth of particles, which can decease the dielectric dissipation and improve the withstand voltage greatly. With adding 2.5mol% NiNb₂O₆, 1.5mol% CaZrO₃ and 0.1mol% MnCO₃, a kind of MLC ceramic with low frequent and high voltage can be got, which also meets X8R requirement, and its dielectric properties are as follows: ε≥2600, Δ C/C _20℃≤±15% (-55℃-- +150℃), tgδ≤0.7%, E_b≥15kV/mm.

Key words: NiNb2O6, X8R, high voltage, CaZrO3