Diffuse scattering and local structure modeling in ferroelectrics

Abstract

The excellent properties of modern ferroelectrics are the result of nanoscale local structure phenomena. Diffuse scattering, sensitive to the atomic correlations, is one of the few techniques that is able to provide detailed information on the local polar order. A review of diffuse scattering studies in ferroelectrics is given with special emphasis on those works where computer simulation techniques are used to analyse the experimental data. The examples comprise some well known materials, such as NaNO 2 or BaTiO 3 , but also modern ferroelectrics: lead-based relaxors, bismuth pyrochlores and BaTiO 3 related solid solutions.

Evidence for anisotropic polar nanoregions in relaxor Pb(Mg1/3Nb2/3)OStock1, Gehring2, Hiraka3 et al. 2012Phys. Rev. B264250View full textAdd to dashboardCite

“…25,26 Moreover, various diffraction studies of single-crystal PMN doped with 10% and 20% PT (PMN-xPT) show that while the near-surface regions (probed by x rays) are rhombohedrally distorted, 27 the interior or bulk of these crystals (probed by neutrons) remains metrically cubic down to low temperatures, thus confirming the skin effect in this system. 28,29 Subsequent neutron-based strain experiments found a significant skin effect in large single crystals of PMN as well that has since been observed with x rays, 26,[30][31][32] and local regions of polarization have been directly imaged near the surface using piezoresponse force microscopy. 33 Under the application of strong electric fields, the bulk unit cell in PMN remains cubic, whereas the structure of the near-surface region distorts; however, the intensity of the diffuse scattering arising from short-range polar correlations can be suppressed by an external electric field, but only below the critical temperature T C ∼ 210 K, which is indicative of a more ordered structure in the material.…”

Atomistic modeling of diffuse scattering in cubic PbZrO3

“…In general, the intensity distribution is similar to those observed for Pb-based relaxor FEs. [11,12] The main differences are (1) in the case of PZO, less DS intensity is concentrated around reciprocal lattice nodes, (2) consequently, the streaks extend towards the edges of Brillouin zones (BZ) and (3) there is a checkerboard background pattern pronounced close to h 100 i and fading out towards h 110 i radial lines. Similarly to relaxors, [13] there is a visible intensity maximum in the vicinity of (but not exactly at) some M points of the BZ, e.g.…”

Disorder and Transport Properties of In3SbTe2 – an X‐ray, Neutron and Electron Diffraction Study

“…Such diffuse intensities are known from intermetallics like Ni 0.9 Al 0.1 as well as from ferroelectrics like PbZn 0.33 Nb 0.67 O 3 , although there they are sometimes accompanied by further short-range order effects or superstructure formation. [17][18][19] There is no significant intensity variation on the streaks; therefore displacements in IST exhibit no pronounced short-range order.…”