Two-component model of the neutron diffuse scattering in the relaxor ferroelectric PZN-4.5% PT

We report measurements of the neutron diffuse scattering in a single crystal of the relaxor ferroelectric material 95.5% Pb(Zn1/3Nb2/3)O-3-4.5% PbTiO3. Our results suggest that the nanometer scale structure in this compound exhibits both < 100 > and < 110 > polarizations, which contribute to different portions of the total diffuse scattering intensity. These contributions can be distinguished by the differing responses to an electric field applied along [001]. While diffuse scattering intensities associated with < 110 > (T2-type) polarizations show little to no change in a [001] field, those associated with < 100 > (T1-type) polarizations are partially suppressed by the field at temperatures below the Curie temperature T-C similar to 475 K. Neutron spin-echo measurements show that the diffuse scattering at (0.05,0,1) is largely dynamic at high temperature and gradually freezes on cooling, becoming mostly static at 200 K.