A new type of dielectric composite with X7R characteristic and high dielectric constant

A new dielectric composite for capacitors, with a high dielectric constant in excess of 9000 at 25°C and low-sintering temperature, has been successfully developed by sintering layer-like-structure green body made up of four types of calcined Pb-based complex perovskite with different Curie temperatures. It can well satisfy the X7R EIA specification. Dielectric measurements showed that the as-sintered layer-like dielectric is a multiphasic ceramic composite. The flat dielectric-temperature characteristic was considered to come from the macroscopical inhomogeneity. The effects of stacking order on the dielectric properties of the composite were found. An optimum stacking procedure was identified.