The re
lative stabi
lity o
f mu
lti
ferroic BiFeO
3 (0001) sur
faces, which is the (111)
facet in the pseudocubic notation, with di
fferent stoichiometry is systematica
lly studied by using
ab initio thermodynamic approach in order to obtain insights into the stab
le sur
face terminations. We predict that under most chemica
l potentia
l conditions the thermodynamica
lly
favored terminations
for the negative and positive sur
faces are −Bi–O
2 and −Fe–O
3–Bi, respective
ly. The predicted di
fference in oxygen content between the negative and positive sur
faces is consistent with experimenta
l observations at the BiFeO
3/meta
l inter
faces (
Nat. Mater.,
lass="NLM_x">lns:mml="http://www.w3.org/1998/Math/MathML" xmlns:ACS="http://namespace.acs.org/2008/acs" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:space="preserve"> 2014
lass="NLM_x">lns:mml="http://www.w3.org/1998/Math/MathML" xmlns:ACS="http://namespace.acs.org/2008/acs" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:space="preserve">, 13lass="NLM_x">lns:mml="http://www.w3.org/1998/Math/MathML" xmlns:ACS="http://namespace.acs.org/2008/acs" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:space="preserve">, 1019, DOI:
f="http://www.nature.com/nmat/journal/v13/n11/abs/nmat4058.html" class="extLink">10.1038/nmat4058; Adv. Mater.,lass="NLM_x">lns:mml="http://www.w3.org/1998/Math/MathML" xmlns:ACS="http://namespace.acs.org/2008/acs" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:space="preserve"> 2015lass="NLM_x">lns:mml="http://www.w3.org/1998/Math/MathML" xmlns:ACS="http://namespace.acs.org/2008/acs" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:space="preserve">, 27lass="NLM_x">lns:mml="http://www.w3.org/1998/Math/MathML" xmlns:ACS="http://namespace.acs.org/2008/acs" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:space="preserve">, 6934, DOI: f="http://onlinelibrary.wiley.com/doi/10.1002/adma.201502754/suppinfo" class="extLink">10.1002/adma.201502754). We determine the atomic geometries and electronic states as well as the magnetic properties for the negatively and positively polarized stable surfaces. Our results demonstrate that not only the stoichiometry and atomic geometries but also the electronic and magnetic properties of the BiFeO3 (0001) surfaces show strong dependence on the ferroelectric polarization direction. Therefore, we expect that the surface physical and chemical properties of the BiFeO3 (0001) surfaces can be easily tuned by an external electric field.