Related papers: First-principles study of multiferroic RbFe(MoO$_4…
We have studied the high temperature multiferroic cupric oxide using polarized neutron diffraction as a function of temperature and applied electric field. We find that the chiral domain population can be varied using an external electric…
The phenomenological theory of ferroelectricity in spiral magnets presented in [M. Mostovoy, Phys. Rev. Lett. 96, 067601 (2006)] is generalized to describe consistently states with both uniform and modulated-in-space ferroelectric…
The crystal and magnetic structure of multiferroic LiFe(WO$_4$)$_2$ were investigated by temperature and magnetic-field dependent specific heat, susceptibility and neutron diffraction experiments on single crystals. Considering only the two…
A layered iron oxide \rfeo ($R$: rare-earth elements) is an exotic dielectric material with charge-order (CO) driven electric polarization and magnetoelectric effect caused by spin-charge coupling. In this paper, a theory of electronic…
In this contribution to the special issue on multiferroics we focus on multiferroicity driven by different forms of charge ordering. We will present the generic mechanisms by which charge ordering can induce ferroelectricity in magnetic…
The magnetic structures which endow TbMnO$_3$ with its multiferroic properties have been reassessed on the basis of a comprehensive soft x-ray resonant scattering (XRS) study. The selectivity of XRS facilitated separation of the various…
We demonstrate that small but finite ferroelectric polarization ($\sim$0.01 $\mu$C/cm$^2$) emerges in orthorhombic LuFeO$_3$ ($Pnma$) at $T_N$ ($\sim$600 K) because of commensurate (k = 0) and collinear magnetic structure. The synchrotron…
We use a combination of symmetry arguments and first-principles calculations to explore the connection between structural distortions and ferroelectricity in the perovskite family of materials. We explain the role of octahedral rotations in…
Ferroelectric properties in magnetic fields of varying magnitude and direction have been investigated for a triangular-lattice helimagnet CuFe1-xGaxO2 (x=0.035). The magnetoelectric phase diagrams were deduced for magnetic fields along…
We clarify that the antiferromagnetic order in the distorted tetrahedral quasi-one dimensional spin system induces electric polarizations. In this system, the effects of the low dimensionality and the magnetic frustration are expected to…
We present a phenomenological model for magnetoelectricity in multiferroic materials. The distinctive feature of the model is a two-component complex order parameter that encodes the electric polarization, along with a direct coupling…
The magnetic field induced rearrangement of the cycloidal spin structure in ferroelectric mono-domain single crystals of the room-temperature multiferroic BiFeO$_3$ is studied using small-angle neutron scattering (SANS). The cycloid…
Using combined theoretical and experimental approaches, we studied the structural and electronic origin of the magnetic structure in hexagonal LuFeO$_3$. Besides showing the strong exchange coupling that is consistent with the high magnetic…
Magnetoelectric crystals have the interesting property that they allow electric fields to induce magnetic polarizations, and vice versa, magnetic fields to generate ferroelectric polarizations. Having such a magnetoelectric coupling usually…
Ferroelectricity is usually found in compound materials composed by different elements. Here, based on first-principles calculations, we reveal the first example of spontaneous electrical polarization and ferroelectricity in stable…
Ferroelectric materials are characterized by a spontaneous polar distortion. The behavior of such distortions in the presence of free charge is the key to the physics of metallized ferroelectrics in particular, and of structurally-polar…
A wide variety of applications has inspired great interest in designing new materials and investigating fundamental physics in the ferroelectric field. In the concept of ferroelectricity, the spontaneous polarization is traditionally…
Recent interests towards novel functionalities arising at domain walls of ferroic materials naturally call for a microscopic understanding. To this end, first-principles calculations have been performed in order to provide solid evidence of…
Competing interactions and geometric frustration provide favourable conditions for exotic states of matter. Such competition often causes multiple phase transitions as a function of temperature and can lead to magnetic structures that break…
The ferroelectricity of the spiral magnets LiCu2O2 and LiCuVO4 was examined by calculating the electric polarizations of their spin spiral states on the basis of density functional theory with spin-orbit coupling. Our work unambiguously…