Local polarization distribution and Edwards-Anderson order parameter of relaxor ferroelectrics

The temperature dependence of the Edwards-Anderson order parameter YEA and the local polarization distribution function W((p) over right arrow) have b een determined in a PMN single crystal via 2D Nb-93 NMR. A glasslike freezi ng of reorientable polar clusters occurs in the temperature range of the di ffuse relaxer transition, whereas the NMR spectra corresponding to pinned n anodomains do nut change with temperature. The obtained form of W((p) over right arrow) as well as the temperature dependence of q(EA) and the nonline ar dielectric susceptibility can be well described by a newly proposed sphe rical random bond-random field model of relaxer ferroelectrics.