Equivalent circuit analysis for ferroelectrics

The purpose of this study is to make up the equivalent circuit for bulk relaxation, in which excluded a grain boundary and electrode relaxation, and to simulate its impedance under various conditions. As ac held applied to dielectric or ferroelectric materials, the dipole displacement and the charge carrier migration occur simultaneously. With constructing the Debye equivalent circuit and a single RC circuit in parallel(briefly DRC), two dispersions in only grain may be interpreted. The parameters in DRC circuit is estimated on the basis of real situation. As a result of simulation, (i) the resistance for DRC is affected by only R-h not R-d, even if R-d < R-h, and (ii) the relaxation behavior significantly varied according to the ratios, R-h/R-d and C-h/C-d2. The most relaxation behaviours of dielectrics and ferroelectrics can be represented with a combination of parameters in DRC, not including the complicate mathematics.