Grain Size Dependence of Dielectric Constant for Modified (Pb0.63Ba0.37)(Zr0.7Ti0.3)O3Ceramic Material

Abstract

The grain size dependence of the dielectric constant for a modified (Pb_0.63Ba_0.37)(Zr_0.7Ti_0.3)O₃material from -55° C to 150° C has been studied. Grain sizes in the range of 1.2 µ m to 7.0 µ m were prepared by varying the sintering temperature and time. The maximum dielectric constant decreased monotonously as the grain size decreased. The dielectric constant at a lower temperature for the ferroelectric phase (-55° C) also decreased monotonously. However, at a high temperature for the cubic phase (150° C), the dielectric constant was almost constant. This monotonous decrease of the dielectric constant at a lower temperature is the same phenomenon as for the Pb(Mg_1/3Nb_2/3)O₃material. The Curie temperature of the ceramic shifted toward a higher temperature as the grain size was reduced. However, the aging rate was almost independent of the grain size.