Development of an Atomic Level Model for BiFeO3 from First-Principles.

M. GRAF; M. SEPLIARSKY; M. G. STACHIOTTI; S. TINTE

Krakovia

Congreso; 13th International Meeting on Ferroelectricity (IMF-13); 2013

p { margin-bottom: 0.21cm; direction: ltr; line-height: 120%; text-align: left; widows: 2; orphans: 2; }p.western { font-family: "Calibri",serif; }p.cjk { font-family: "Times New Roman"; }p.ctl { font-family: "Calibri"; } We develop a first-principles atomistic shell model for BiFeO3 to study its ferroelectric and structural properties at finite temperature. The parameters of the potential are adjusted to reproduce first-principles results in different relevant configurations. Molecular Dynamics simulations show that the resulting model is able to describe the ground-state ferroelectric R3c structure which remains stable as the temperature increases. At about 1100 K, system displays a first-order phase transition to the paraelectric Pbnm phase. Our results indicate that the developed model captures the delicate structural behavior showed by the ab-initio calculations and is able to reproduce the temperature behavior observed in experiments.