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 (Zn_1/3Nb _2/3)O₃-4.5%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 ∼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.