Diffuse scattering from the lead-based relaxor ferroelectric PbMg_1/3Ta_2/3O_3
Abstract
The relaxor ferroelectric PbMg_1/3Ta_2/3O_3 was studied by single-crystal neutron and synchrotron x-ray diffraction and its detailed atomic structure has been modeled in terms of static Pb-displacements that lead to the formation of polar nanoregions. Similar to the other members of the Pb-based relaxor family like PbMg_1/3Nb_2/3O_3 or PbZn_1/3Nb_2/3O_3 the diffuse scattering in the [H,0,0]/[0,K,0] scattering plane has a butterfly-shape around the (h,0,0) Bragg reflections and is transverse to the scattering vector for (h,h,0) peaks. In the [H,H,0]/[0,0,L] plane the diffuse scattering is elongated along the <1,1,2> directions and is transverse to the scattering vector for (h,h,h) reflections. We find that a model consisting of correlated Pb-displacements along the <1,1,1>-directions reproduces the main features of the diffuse scattering in PbMg_1/3Ta_2/3O_3 adequately when the correlation lengths between the Pb-ion displacement vectors are longest along the <1,1,1> and <1,-1,0> and shortest along <1,1,-2> directions.
Keywords
Cite
@article{arxiv.0908.2920,
title = {Diffuse scattering from the lead-based relaxor ferroelectric PbMg_1/3Ta_2/3O_3},
author = {A. Cervellino and S. N. Gvasaliya and O. Zaharko and B. Roessli and G. M. Rotaru and R. A. Cowley and S. G. Lushnikov and T. A. Shaplygina and M. -T. Fernandez-Diaz},
journal= {arXiv preprint arXiv:0908.2920},
year = {2009}
}
Comments
17 pages, 3 figures, submitted to Phys. Rev. B. Version2: revised with minor corrections