INVESTIGADORES
SEPLIARSKY Marcelo Claudio
congresos y reuniones científicas
Título:
Firs-principles based atomistic modeling of BiFeO3
Autor/es:
M. GRAF; M. SEPLIARSKY; M. G. STACHIOTTI; S. TINTE
Lugar:
Montevideo
Reunión:
Workshop; V Workshop on Novel Methods for Electronic Structure Calculations.; 2013
Resumen:
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The
combination of first-principles calculations with classical atomic
models is a powerful approach to the investigation of systems where a
large number of atoms are involved, to the study of compositional
effects in solid solutions,
and to the computation of finite temperature properties in oxide
materials. Among these methods, molecular dynamics simulations with
atomic level models fitted to first-principles calculations have been
shown to be very successful for predicting the qualitative behavior
of pure compounds and solid solutions. In this work we apply a shell
model description in order to study the structural and ferroelectric
properties of the multiferroic perovskite BiFeO3
as a function of temperature and under the effects of an external
electric field. The
developed model is able to capture the delicate structural behavior
showed by first-principlescalculations,
and it reproduces satisfactorily the temperature behavior observed in
experiments. The simulations show that the rhombohedral ground state
of R3c
symmetry remains stable up to TC
= 1100 K. At this temperature a strong first order transition to an
orthorhombic phase of Pbnm
symmetry takes place. A detailed analysis of the structure and the
behavior of the system under an electric field indicate the
antiferroelectric nature of this high temperature phase.