Ceramics with Ultrahigh Permittivity Values: Compositions, Synthesis Methods, and Properties at Low and Medium Frequencies

A review of dielectric materials with high (exceeding 10,000) values of relative permittivity is presented. Most of the compositions of these materials are based on systems that include ferroelectric and non-ferroelectric components, as well as solid solutions based thereon. Various approaches to increasing the permittivity of materials are considered, including doping, sintering atmosphere, grinding time, sintering temperature, and grain size. The effect of dopants and the synthesis method on the characteristics of capacitor ceramics that can be used in the low-frequency and high-frequency range are compared.