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

Abstract

The Pb207, Sc45, and Nb93 nuclear magnetic resonance spectra have been measured for the relaxor ferroelectric single crystal Pb(Sc1/2Nb1/2)O3 both above and below Tc. The Sc45 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 Tc in both the ordered as well as in the disordered regions. The Edwards–Anderson order parameter q similarly increases linearly with decreasing T below Tc. For the disordered region we find J0≈328 K and J≈227 K whereas Δ/J02≈0.006. In the ordered region J0≈297 K, whereas J and Δ 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.