Ferroelectric and antiferromagnetic domain wall

It has been experimentally confirmed that the ferroelectric (FEL) and antiferromagnetic (AFM) order-parameter in hexagonal YMnO 3 are coupled at the FEL domain boundary. A microscopic model for this clamping of the two order-parameters is proposed. The clamping can be understood as due to the change of exchange integrals induced by the spin–orbit interaction and low symmetry field within the FEL domain boundary and due to spin anisotropy energy which depends on the sign of FEL polarization.