Multiferroics and magnetoelectrics with coexisting and coupled multiple ferroic orders are materials promising new technological\ud advances. While most studies have focused on single-phase or heterostructures of inorganic materials, a new class of materials\ud called metal–organic frameworks (MOFs) has been recently proposed as candidate materials demonstrating interesting new routes\ud for multiferroism and magnetoelectric coupling. Herein, we report on the origin of multiferroicity of (CH3)2NH2Mn(HCOO)3 via direct\ud observation of ferroelectric domains using second-harmonic generation techniques. For the first time, we observe how these\ud domains are organized (sized in micrometer range), and how they are mutually affected by applied electric and magnetic fields.\ud Calculations provide an estimate of the electric polarization and give insights into its microscopic origin

The optical magnetoelectric (ME) effect, i.e., the change of optical absorption upon the reversal of the light propagation direction, has been investigated for a polar ferrimagnet GaFeO3. For dipole- and spin-forbidden d-d transition bands located at 1.2-2.3 eV, a clear signal of the optical ME effect (Deltaalphat approximately 3x10(-3)) is observed with an applied magnetic field as low as 500 Oe and a sample thickness (t) of 50 microm. The observation of a large ME effect in the present compound suggests a possible route to magnification of this novel phenomenon for application.

The manipulation of domains by external fields in ferroic materials is of major interest for applications. In multiferroics with strongly coupled magnetic and electric order, however, the magnetoelectric coupling on the level of the domains is largely unexplored. We investigated the field-induced domain dynamics of TbMnO3 in the multiferroic ground state and across a first-order spin-flop transition. In spite of the discontinuous nature of this transition, the reorientation of the order parameters is deterministic and preserves the multiferroic domain pattern. Landau-Lifshitz-Gilbert simulations reveal that this behavior is intrinsic. Such magnetoelectric correlations in spin-driven ferroelectrics may lead to domain wall-based nanoelectronics devices.