Domain wall contributions in Pb ( Zr , Ti ) O 3 ceramics at morphotropic phase boundary: A study of dielectric dispersion

The dielectric properties of undoped, Nb-, and Fe-doped Pb ( Zr , Ti ) O 3 ceramics with composition near morphotropic phase boundary were investigated in the frequency range from 1 MHz to 20.2 GHz at room temperature. Temperature dependences of dielectric permittivity ε ′ and loss ε ″ are measured at 100 kHz from 50 to 300 K and around 13.4 GHz from 100 to 300 K. These measurements permit estimation of the upper limit of the intrinsic permittivity and lower limit of the extrinsic contributions to the permittivity as a function of temperature. The extrinsic contributions account for more than 50% of the quasistatic dielectric permittivity in studied samples.