Multiferroic Domain Structure in Orthorhombic Multiferroics of Cycloidal Spin Order: Three-Dimensional Phase Field Simulations

The three-dimensional (3-D) multiferroic domain patterns in multiferroic rare-earth manganites of the -plane cycloidal spin (CS) order and -plane CS order are investigated by means of Monte Carlo simulation based on the multiferroic Heisenberg model and phase-field simulation based on the time-dependent Ginzburg-Landau equation. It is revealed that the ferroelectric domains associated with both the -plane CS order and -plane CS order align in the 180°-domain pattern with polarization parallel with domain walls. The mechanism dominating the domain patterns is discussed.