Grain size dependence of dielectric and electrostriction of Pb(Mg_1/3Nb_2/3)O₃-based ceramics

The dielectric and electrostrictive properties of relaxor ferroelectric Pb(Mg]/3Nb2/3)03-based ceramics are strongly affected by the microstructure with emphasis on the grain size. Both the dielectric constant K and electrostrictive field coefficient (M) were found to increase with increasing grain size whereas the electrostrictive polarization coefficient Q was essentially independent of preparation. It was observed, however, that factors other than grain size, such as diffuseness of the phase transition, must also be taken into account to explain microstructural effects on various properties of relaxor dielectrics.