Abstracts Book - IMRC 2018

• SD1-O033
FERROMAGNETISM VS ANTIFERROMAGNETISM IN BIFEO3 BY
FIRST PRINCIPLES CALCULATION
H´ Linh H´ Mok 1 , Espiridión Martínez Aguilar 1 , Joel Antúnez García 2 , Jordi Ribas Ariño 3 , Lourdes
Mestres Vila 4 , Pere Alemany 5 , Donald H. Galvan 2 , Jesús María Siqueiros Beltrones 6 , Oscar
Raymond Herrera 6
1 Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Posgrado en
Fisica de Materiales, Mexico. 2 Centro de Nanociencias y Nanotecnología CNyN-UNAM,
Departamento de Física de Superficies, Mexico. 3 Universitat de Barcelona, Departament de
Ciencia de Materials i Química Física, Spain. 4 Universitat de Barcelona, Departament de
Química Inorgànica, Spain. 5 Universitat de Barcelona, Departament de Química Física, Spain.
6 Centro de Nanociencias y Nanotecnología CNyN-UNAM, Departamento de Materiales
Avanzados, Mexico.
Multiferroic materials such as BiFeO 3 (BFO) have received a great deal of
attention due to their potential applications as magnetoelectric devices. At room
temperature, BFO is a single-phase magnetoelectric multiferroic with
antiferromagnetic (AFM) and ferroelectric (FE) ordering that exhibits high
spontaneous polarization. The absence of macroscopic ferromagnetism (FM) in
BFO limits its practical applications. Recently, a novel ferromagnetic state
coexisting with ferroelectric ordering at room temperature has been reported
in (012)-oriented and strained BFO thin films (with thickness ≤ 50 nm) grown on
La 0.7 Sr 0.3 MnO 3 /SiO 2 /Si(100) using the sputtering technique (Acta Materialia 128,
2017, 451-454). This means that under strict deposit conditions it is possible to
obtain BFO material with ferromagnetic and ferroelectric ordering. This
achievement opens up a new world of BFO applications taking advantage of the
FE-FM ordering coexistence. To date, there are many detailed theoretical studies
on BFO with FE-AFM ordering; however, only a few on BFO with FE-FM ordering
are found in the literature. Therefore, it seems necessary to study, by first
principles, the magnetic order in bulk BFO involving a meticulous comparison
between antiferromagnetic and ferromagnetic ordering.The aim of this
theoretical work was to study the existence and stability of a ferromagnetic
order in bulk BFO as compared with the natural AFM order, based on the
experimental evidence observed in BFO/LSMO heterostructures For that, a bulk
BFO unit cell was constructed using the structural parameters taken previous
studies. The electronic, structural, and magnetic properties of BFO were
calculated with Density Functional Theory (DFT) + Hubbard potential (U)
formalism using the Quantum Espresso package, while the spontaneous
polarization was computed by means of the Modern Theory of Polarization.