Nuclear magnetic resonance study of the relaxor ferroelectric Pb(Sc1/2Nb1/2)O-3

The Pb-207, Sc-45, and Nb-93 nuclear magnetic resonance spectra have been m easured for the relaxor ferroelectric single crystal Pb(Sc1/2Nb1/2)O-3 both above and below T-c. The Sc-45 spectra suggest that the "disordered" part of the crystal occupies about 60% and the "ordered" cubic part about 40% of the crystal volume. In agreement with the spherical random bond-random fie ld (SRBRF) model the square of the polarization linearly increases with dec reasing T below T-c in both the ordered as well as in the disordered region s. The Edwards-Anderson order parameter q similarly increases linearly with decreasing T below T-c. For the disordered region we find J(0)approximate to 328 K and J approximate to 227 K whereas Delta /J(0)(2)approximate to0.0 06. In the ordered region J(0)approximate to 297 K, whereas J and Delta are too small to be determined from this experiment. The results demonstrate t hat the SRBRF model works not only for pure relaxors but also for relaxor f erroelectrics. (C) 2001 American Institute of Physics.