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S e p t e m b e r 2 4 - 2 6 , 2 0 1 8 | B u d a p e s t , H u n g a r y
Magnetic Materials 2018
Page 40
MAGNETISM AND
MAGNETIC MATERIALS
2nd International Conference on
Materials Science and Nanotechnology | Volume 2
OF EXCELLENCE
IN INTERNATIONAL
MEETINGS
YEARS
Marie-Bernadette Lepetit, Mater Sci Nanotechnol 2018, Volume 2
THE ROLE OF THE RARE-EARTH ON THE
MANETO-ELECTRIC COUPLING: THE
RMN2O5 FAMILY
Magneto-electric, multiferroic material have attracted a lot of attention in
the last decade due to their ability to control their polarization or dielectric
constant using a magnetic field, or to control their magnetic order using an
electric field. Among these materials the RMn2O5 family is a prototypal system
as in some of its members the coupling between the electric and magnetic
properties is among the largest, as was first shown by Hur et al. In the RMn2O5
family the magneto-electric coupling originates in the release of the magnetic
frustration between the manganese ions. However, according to the nature of
the rare-earth, the coupling can either be large as in the Tb compoud or nill as
in the Sm one. Similarly, the polarization can take quite different values. For
instance, the GdMn2O5 compound exhibits an extremely large polarization of
about 3600μC/m2. In this talk we will try to present a comprehensive model
explaining the role of the rare earth both on the existence of a magneto-electric
coupling and the magnetic order, as well as on the polarization amplitude.
Figure.1: Atomic displacements associated with the release the magnetic
frustration at the origin of the polarization.
Recent Publications
1. G Yahia, F Damay, S Chattopadhyay, V Balédent, W Peng, E Elkaim, M
Biography
Marie-Bernadette Lepetit has completed her PhD at
the Université Paul Sabatier in Toulouse France on
the ab-initio treatment of the electronic correlation.
She has obtained a research position in the Labora-
toire the Physique Quantique, CNRS in 1988 where
she stayed until 2004. In 2004, she moved to the
CRISMAT in Caen as a CNRS Director of research
where she initiated a theory group. In 2012, she then
moved to Grenoble where she joined the Institut
Néel and Institut Laue Langevin where she headed
the theory group until recently. From 2008 to 2015,
she headed the French National Research Group
(GdR) on strongly correlated materials gathering
more than 450 researchers. Recently she is heading
the committee program for high performance com-
puting in chemistry and is member of the French
National Committee for Scientific Research (elec-
tronic structure in condensed matter section). She
is a Theoretician, specialist of the ab-initio treatment
of electronic and magnetic excitation in strongly
correlated materials. She works at the interface of
solid state physics and quantum chemistry and
aims at solving the structure-properties relation-
ships in strongly correlated systems.
Marie-Bernadette Lepetit
Institut Laue Langevin, France