Converse Magnetoelectric Effect in Epitaxial Co₂MnSi/Pb(Mg1/3Nb2/3)O₃-PbTiO₃ Multiferroic Heterostructures

We experimentally study a strain-meditated converse magnetoelectric (CME) effect in multiferroic heterostructures consisting of Co
₂
MnSi and Pb(Mg
_1/3
Nb
_2/3
)O
₃
-PbTiO
₃
(PMN-PT). To investigate the CME effect, Co
₂
MnSi films are grown on PMN-PT(001) at various growth temperatures by molecular beam epitaxy. Using magneto-optical Kerr-effect and strain measurements, we find that the remanent magnetization state only for the
$L 2_{1}$
-ordered Co
₂
MnSi/PMN-PT is modulated by the application of the lattice strain, while that for the
$B2$
-ordered Co
₂
MnSi/PMN-PT is insensitive to the strain. We conclude that the formation of
$L 2_{1}$
-ordered structure is needed to obtain an effective CME effect in the Co
₂
MnSi/PMN-PT multiferroic heterostructure.