Development of a Shell Model Potential for Molecular Dynamics for PbTiO3 by Fitting First Principles Results

M. SEPLIARSKY; R. E. COHEN

AIP CONFERENCE PROCEEDINGS

AIP Publishing

Lugar: Washington DC; Año: 2002 vol. 626 p. 36 - 42

0094-243X

Atomistic potentials are desirable for studying the dynamics and effects of temperature on electromechanical properties of piezoelectrics. We development a shell model to study PbTiO3, which is an important component in many piezoelectric solid solutions. With parameters completely adjusted to available first principle calculations, the model describes the temperature behavior of the system in good agreement with experiments. At P = 0, however, the potential gives a antiferrodistortive instability, which coexists with the ferroelectric distortion. The instability disappears at a pressure of 0.5 GPa.