FREQUENCY-DEPENDENT DIELECTRIC-CONSTANT USING GENERALIZED LANGEVIN EQUATION

Generalized Langevin equation for the hopping charge carrier is used t o calculate the frequency-dependent complex dielectric constant. Space charge effect to the complex dielectric constant is considered to exp lain the strong low frequency dispersion of real part of dielectric co nstant. Using this equation, frequency-dependent dielectric constants at various temperatures for amorphous KNbO3, KNbO3, and PbTiO3 are fit ted, and the conduction mechanisms are discussed.