, Volume 41, Issue 5, pp 1110-1118,
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Monte Carlo Simulation Study of Diffuse Scattering in PZT, Pb(Zr,Ti)O3

Abstract

Transverse polarized diffuse streaks have been observed in diffraction patterns of Pb(Zr1−x Ti x )O3 (PZT) ceramics for compositions ranging from x = 0.3 (rhombohedral phase) to x = 0.7 (tetragonal phase) including the important morphotropic phase boundary (MPB) region (x = 0.48). The streaks correspond to diffuse planes of scattering in three dimensions, and these are oriented normal to the (cubic) $ \langle 111\rangle_{c} $ directions. A Monte Carlo (MC) model has been developed that convincingly reproduces the observed diffraction patterns. In this model, the displacements of Pb ions running in chains along each of the $ \langle 111\rangle_{c} $ directions are directed along the chain and are strongly correlated from cell to cell. There is no evidence of lateral correlation. Neighboring chains are essentially independent. At this stage, it is not clear what role the local order revealed by the scattering might play in governing the exceptional piezo-electric properties of the material, but its presence requires the currently accepted models for the average structure to be reassessed.

This article is based on a presentation given in the symposium entitled “Neutron and X-Ray Studies for Probing Materials Behavior,” which occurred during the TMS Spring Meeting in New Orleans, LA, March 9–13, 2008, under the auspices of the National Science Foundation, TMS, the TMS Structural Materials Division, and the TMS Advanced Characterization, Testing, and Simulation Committee.
An erratum to this article can be found at http://dx.doi.org/10.1007/s11661-009-9972-4