C. Vecchini

Electric Field Switching of Antiferromagnetic Domains in YMn2O5 : A Probe of the Multiferroic Mechanism

We employ neutron spherical polarimetry to determine the nature and population of the coexisting antiferromagnetic domains in multiferroic YMn2O5. By applying an electric field, we prove that reversing the electrical polarization results in the population inversion of two types of in-plane domains, related to each other by inversion. Our results are completely consistent with the exchange-striction mechanism of ferroelectricity, and support a unified model where cycloidal ordering is induced by coupling to the main magnetic order parameter.

Cu3Nb2O8: A Multiferroic with Chiral Coupling to the Crystal Structure

By combining bulk properties, neutron diffraction, and nonresonant x-ray diffraction measurements, we demonstrate that the new multiferroic Cu(3)Nb(2)O(8) becomes polar simultaneously with the appearance of generalized helicoidal magnetic ordering. The electrical polarization is oriented perpendicularly to the common plane of rotation of the spins-an observation that cannot be reconciled with the conventional theory developed for cycloidal multiferroics. Our results are consistent with coupling between a macroscopic structural rotation, which is allowed in the paramagnetic group, and magnetically induced structural chirality.

Incommensurate magnetic structure of YMn 2 O 5 : A stringent test of the multiferroic mechanism

We have determined the magnetic structure of the low-temperature incommensurate phase of multiferroic

Giant Tunability of Ferroelectric Polarization in GdMn2O5

{\text{YMn}}_{2}{\text{O}}_{5}

Negative Thermal Expansion in Hybrid Improper Ferroelectric Ruddlesden-Popper Perovskites by Symmetry Trapping

using single-crystal neutron diffraction. By employing corepresentation analysis, we have ensured full compliance with both symmetry and physical constraints, so that the electrical polarization must lie along the

Magnetoelastic coupling in the frustrated antiferromagnetic triangular lattice CuMnO2

b

Substitution Effect on the Interplane Coupling in Crednerite: the Cu1.04Mn0.96O2 Case

axis, as observed. The evolution of the spin components and propagation through the commensurate-incommensurate phase boundary identifies the exchange-striction mechanism as the primary driving force for ferroelectricity.