High energy (67 keV) x-ray diffuse scattering measurements were performed on single crystals of Pb(Zn1/3Nb2/3)O3-xPbTiO3 (PZN-xPT). A novel technique was developed to map out the diffuse scattering distribution in all three dimensions around a large number of Bragg peaks simultaneously, taking advantage of the almost flat Ewald sphere of the high energy x-ray beam. For x=0,4.5, and 8%, the results are very similar, indicating same type of correlations of polarizations in these compounds. Our results show that the diffuse scattering intensity consists of six <110> rod-type intensities around reciprocal lattice points. These rod-type intensities are very likely due to condensations of soft optic phonon modes, polarized in the perpendicular <11ˉ0> directions. A simple model is suggested where these soft phonon modes condense into static \{110\} type planar or ``pancake'' shaped correlations of the in-plane <11ˉ0> polarizations.
@article{arxiv.cond-mat/0404621,
title = {3-D mapping of diffuse scattering in PZN-xPT},
author = {Guangyong Xu and Z. Zhong and H. Hiraka and G. Shirane},
journal= {arXiv preprint arXiv:cond-mat/0404621},
year = {2007}
}
Comments
Resolution/color of many figures are greatly reduced. For a higher resolution version, go to http://neutrons.phy.bnl.gov/~neutron/PZN_diffuse_3.pdf