Nuclear magnetic resonance study of the relaxor ferroelectric Pb(Sc1/2Nb1/2)O3

The Pb-207, Sc-45, and Nb-93 nuclear magnetic resonance spectra have been measured 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 field (SRBRF) model the square of the polarization linearly increases with decreasing T below T-c in both the ordered as well as in the disordered regions. 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 to0.006. 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 that the SRBRF model works not only for pure relaxors but also for relaxor ferroelectrics. (C) 2001 American Institute of Physics.