Barium titanate ceramics were prepared in laboratory in order to know how the remanent polarization and dielectric properties of BaTiO3 ceramic elements were effected by firing temperature and BaO, TiO2 mole ratio used making BaTiO3.
Test pieces were prepared from the lots in which BaO, TiO2 mol ratio were changed from 0.990:1.000 to 1.020:1.000, and fired to the temperature ranging from 1350°C to 1460°C.
The results obtained may be summarized as follows. (1) In general, bodies deficient TiO2 gave the test disks with increasing abnormal polarization phenomenon and dielectric loss (2) BaTiO3 ceramics of 1 mole % excess TiO2 did not show the abnormal polarization pheomenon, but the test pieces of decreasing more or less the total remanent polarization. (3) It was found that the abnormal polarization phenomenon resulted from the remains of hexagonal BaTiO3 or Ba2TiO4, BaTi4O9, etc.