Temperature dependent dielectric properties of multilayered
ceramics measured at different frequencies (1, 10, 100, 1000 kHz)
are displayed in Fig. 4. Dielectric constant and loss turn stable
with increasing frequency until the temperature of up to 3001C
since the Curie temperature of the specimen is around 4501C.
Compared with single compositions[12], the composite exhibits
an increased and broadened Curie peak reflecting an integration
effect resulting from the thermal mismatch stress in the gradient
compositions[21]. In terms of the dielectric loss, the composite
reveals a leveling effect which greatly improved the inferior
composition in the multilayer structure.