First principle based phase stability in PMN-xPT

M. SEPLIARSKY; R. E. COHEN

Rio de Janeiro

Conferencia; 11th International Conference on Advanced Materials (ICAM2009).; 2009

 We have applied a shell model potential developed by fitting first principle results to describe the behavior of the relaxorferroelectricPMN-xPT as function of concentration. The solid solution exhibits three regions with different characteristics according to Ticontent in agreement with the experiments. At low Ti the polar and structural disorder dominates, and the symmetry is rhombohedral.The intermediate region is ferroelectric with easy rotation of the polarization direction, and the symmetry is monoclinic. Finally, in thehigh Ti content region, the solid solution adopts a ferroelectric behavior similar to PT, with tetragonal symmetry.