Characterization of Dielectric Relaxation of Relaxor Ferroelectrics

Abstract

The concept ‘relaxativity’ is proposed to describe the degree of dielectric relaxor in relaxor ferroelectrics, like the ‘fragility’ in supercooled liquid in describing glass forming ability during vitrification process. The calculated results of Pb(Mg1/3Nb2/3)O3-PbTiO3 relaxors and BaTiO3-BaZrO3 relaxors exhibit good coincidences with the intervals between their dielectric peak temperatures. The larger relaxativity is corresponding to larger configurational entropy and smaller spatial correlation length, or stronger local interactions for a relaxor.