Assessing segregation effects on multiferroic properties of antiferromagneticweak ferromagnetic coupled systems by analytical HRTEM

Abstract

The interplay of ferroic domain walls with crystalline structures and lattice planar defects becomes rather elaborated in multiferroic materials or in magnetic bilayers and multilayers where magnetic moments of antiferromagnetic and ferromagnetic lattices are coupled at the bilayer interface [1-5]. Single atomic layer and double layers make the antiphase ferroelectric domain walls organized in six-fold vortices in multiferroic materials of the class of the hexagonal rare-earth manganites RMnO3[4,6]. Below TN, the Néel temperature, antiferromagnetic domain walls are coupled to the same antiphase domain walls [3,7,8]. Magnetoelectric coupling exposes the multiferroic nature of these materials [3,4,7]. In addition, the same hexagonal RMnO3 materials often display weak-ferromagnetism of which the origin is poorly understood [1,8,9].