Incompatible magnetic order in multiferroic hexagonal DyMnO3

Magnetic order of the manganese and rare-earth lattices according to different symmetry representations is observed in multiferroic hexagonal (h-) DyMnO3 by optical second-harmonic generation and neutron diffraction. The incompatibility reveals that the 3d-4f coupling in the h-RMnO3 system (R= Sc, Y, In, Dy-Lu) is less rigid than commonly expected. Instead, a triggered magnetic phase transition is introduced that constitutes a framework for magnetic and magnetoelectric coupling effects in the h-RMnO3 system.