抄録
The forsterite-based ceramics doped with CaTiO3 and MgAl2O4 was developed to decrease the temperature dependence of dielectric permittivity. Doping of CaTiO3 into forsterite decreased the temperature coefficient of relative permittivity, TCε, and changed the sign of TCε. When 6mol% and 20mol% of CaTiO3 was doped, the values of TCε were 104 and-129 ppm/K, respectively. However, the values of tan6 increased to 1.8×10-3, and 3.6×10-3, respectively, because of the nucleation of titanite crystals with larger dielectric loss. Further addition of MgAl2O4 lowered the value of tanδ as low as 4×10-4. The decrease in tand may be attributed to the decomposition of titanite crystals by the reaction between spinel and titanite.
