Neutron diffuse scattering of (1 − x)(Na0.5Bi0.5)TiO3–xBaTiO3 relaxor ferroelectric single crystals

Peculiar L-shaped diffuse streaks along <0 0 1>pc were observed in (Na0.5Bi0.5)TiO3 (NBT) below the Burns temperature, revealing the existence of polar nanoregions (PNRs). The displacement of Bi3+ cations is ∼0.26 Å along <0 0 1>pc in the PNRs, with a size of ∼13 Å in NBT. The BaTiO3 doping drives the diffuse scattering patterns to evolve from the L-shape into an ellipsoidal along <0 1 1 >pc in (Na0.5Bi0.5)TiO3–xBaTiO3. An abnormally large correlation length was observed in the morphotropic phase boundary composition with x = 0.05.