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arXiv · 0908.2373

Origin of Diffuse Scattering in Relaxor Ferroelectrics

P. Ganesh·E. Cockayne·M. Ahart·R. E. Cohen·B. Burton·R. J. Hemley·Yang Ren·Wenge Yang·Z-G Ye
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Abstract

High-pressure and variable temperature single crystal synchrotron X-ray measurements combined with first-principles based molecular dynamics simulations study diffuse scattering in the relaxor ferroelectric system PSN (PbSc$_{1/2}$Nb$_{1/2}$O$_3$). Constant temperature experiments show pressure induced transition to the relaxor phase at different temperatures characterized by butterfly and rod shaped diffuse scattering around the $\{$h00$\}$ and $\{$hh0$\}$ Bragg spots, respectively. The simulations reproduce the observed diffuse scattering features as well as their pressure-temperature behavior, and show that they arise from polarization correlations between chemically-ordered regions, which in previous simulations were shown to behave as polar nanoregions. Simulations also exhibit radial diffuse scattering (elongated towards and away from {\bf Q}=(000)), that persists even in the paraelectric phase, consistent with previous neutron experiments on (PbMg$_{1/3}$Nb$_{2/3}$O$_3$) (PMN)

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P. Ganesh, E. Cockayne, M. Ahart, R. E. Cohen, B. Burton, R. J. Hemley, Yang Ren, Wenge Yang, Z-G Ye. 2009-08-17. Origin of Diffuse Scattering in Relaxor Ferroelectrics. https://doi.org/10.1103/physrevb.81.144102

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