Title :
A neutron powder diffraction study of short range order in ferroelectric Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/
Author :
Rosenfeld, H.D. ; Egami, T. ; Bhalla, A.
Author_Institution :
Dept. of Mater. Sci. & Eng., Pennsylvania Univ., Philadelphia, PA, USA
Abstract :
The structure of Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/ (PMN) was investigated using pulsed neutron powder diffraction. Rietveld analysis suggests small displacements of Pb and O atoms, with anomalously large thermal factors. The pair-distribution function (PDF) derived from experiment indicates the presence of short range order. Modeling in real space by fitting to the experimental PDF suggests displacements of lead and oxygen atoms of much larger magnitude than those indicated by the Rietveld analysis. Correlation of these displacements may be related to the onset of bulk ferroelectricity in this material.<>
Keywords :
crystal atomic structure of inorganic compounds; ferroelectric materials; lead compounds; neutron diffraction examination of materials; short-range order; PMN; PbMgO3NbO3; Rietveld analysis; SRO; bulk ferroelectricity; ferroelectric Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/; large thermal factors; neutron powder diffraction study; pair-distribution function; real space modelling; short range order; small displacements; structure; Diffraction; Ferroelectric materials; Lead; Neutrons; Niobium; Powders; Power engineering and energy; Relaxor ferroelectrics; Temperature; X-ray scattering;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
