Shell Modelに基づくPb(Zr,Ti)O_3の原子間ポテンシャルの開発

概要

論文の詳細を見る
Efficient interatomic potentials for Pb (Zr, Ti) O_3 (PZT) crystals, which are intensively applied to ferroelectric devices, are required for the atomic-scale study of the mechanical and electronic behavior of the materials with the increasing demand of further improvement of the devices. In this study, we develop parameters of empirical shell-model potential functions, with which large-scale atomic simulations will be feasible, for the equilibrium lattice parameters and atomic displacements of ferroelectric state and the elastic constants of tetragonal PbTiO_3, PbZrO_3 and PbZr_<0.5>Ti_<0.5>O_3 based on first principles calculations. The potentials individually optimized for PbTiO_3, PbZrO_3 and PbZr_<0.5>Ti_<0.5>O_3, respectively, reproduce both the structures and the elastic constants of each crystal in good accuracy. The potential simulataneously fitted for all the crystals yields the structural parameters successfully, whereas some components of the elastic constants are poorly reproduced.
2006-06-25