Local structure of relaxor Pb(In0.5Nb0.5)O 3 ferroelectrics

Abstract

Pb (In0.5 Nb0.5) O3 (PIN) crystals show different ferroelectric features depending on the thermal treatments applied. Different treatments result in an ordered PIN exhibiting an antiferroelectricity, or a disordered PIN exhibiting relaxor behavior. These crystals were examined using synchrotron x-ray diffraction. In addition to the conventional crystallographic refinement, the atomic pair distribution function (PDF) analysis was used. Crystallographic analysis suggests that the average structure of the ordered PIN is different from that of the disordered PIN. However, the PDF analysis, which is more accurate in describing the local structure, shows that the local environments of the ordered and the disordered PIN crystals are quite similar. The difference between the disordered PIN and the ordered PIN is that the atomic displacement is either correlated or not. © 2006 American Institute of Physics.