Related papers: Giant improper ferroelectricity in the ferroaxial …
By extending our general spin-current model to non-centrosymmetric spin dimers and performing density functional calculations, we investigate the causes for the helical magnetic order and the origin of the giant ferroelectric polarization…
Using first principles calculations, we study the microscopic origin of ferroelectricity (FE) induced by magnetic order in the orthorhombic HoMnO3. We obtain the largest ferroelectric polarization observed in the whole class of improper…
We report that CaMn$_7$O$_{12}$ is a new magnetic multiferroic material. The appearance of a ferroelectric polarization coinciding with the magnetic phase transition ($\sim90$ K) suggests the presence of ferroelectricity induced by…
Orbitally ordered states evolving coincidentally with structural distortions and magnetic ordering provide a novel route to controlling electronic and magnetic properties of materials through external fields. We report an unprecedented…
There has been tremendous research activity in the field of magneto-electric (ME) multiferroics after Kimura et al. [1] showed that antiferromagnetic and ferroelectric order coexist in orthorhom- bically distorted perovskite TbMnO3 and are…
We report $\alpha$-Cu$_2$V$_2$O$_7$ to be an improper multiferroic with the simultaneous development of electric polarization and magnetization below $T_C$ = 35 K. The observed spontaneous polarization of magnitude 0.55 $\mu$Ccm$^{-2}$ is…
The single crystal study of CaBaCo4O7, a non collinear ferrimagnet (TC=64K), with a polar orthorhombic space group (Pbn21) between 4 K and 293 K, shows the appearance below TC of a large electric polarization along its c axis, reaching…
In hybrid improper ferroelectric systems, polarization arises from the onset of successive nonpolar lattice modes. In this work, measurements and modeling were performed to determine the spatial symmetries of the phases involved in the…
Ferroelectricity in the incommensurate helical magnetic phase (below TN, 43K) of alpha CaCr2O4 has been confirmed by pyroelectric measurements. Magnetoelectric and magnetodielectric coupling exist below TN and are proportional to the square…
We report multiferroic behavior in double perovskite Y2CoMnO6 with ferroelectric transition temperature Tc = 80K. The origin of ferroelectricity is associated with magnetic ordering of Co2+ and Mn4+ moments in a up-up-down-down arrangement.…
The noncollinear cycloidal magnetic order breaks the inversion symmetry in CaMn$_{7}$O$_{12}$, generating one of the largest spin-orbit driven ferroelectric polarizations measured to date. In this Letter, the microscopic origin of the…
Cu3Nb2O8 is an unusual multiferroic compound that undergoes a series of magnetic ordering at low temperatures. Concurrent development of electric polarization has been reported at TN1 ~25 K corresponding to a non-collinear helicoidal…
First-principles calculations are presented for the layered perovskite Ca$_3$Mn$_2$O$_7$. The results reveal a rich set of coupled structural, magnetic and polar domains in which oxygen octahedron rotations induce ferroelectricity,…
We have performed dielectric measurements and neutron diffraction experiments on the double perovskite In2NiMnO6. A ferroelectric polarization, P ~ 30 {\mu}C/m2, is observed in a polycrystalline sample below TN = 26 K where a magnetic phase…
Using a joint approach of density functional theory and model calculations, we demonstrate that a prototypical charge ordered half-doped manganite, La$_{1/2}$Ca$_{1/2}$MnO$_3$ is multiferroic. The combination of a peculiar charge-orbital…
Single crystal synthesis, structure, electric polarization and heat capacity measurements on hexagonal InMnO3 show that this small R ion in the RMnO3 series is ferroelectric (space group P63cm). Structural analysis of this system reveals a…
We report a systematic study of the structure, electric and magnetic properties of Ca$_3$Co$_{2-x}$Mn$_x$O$_6$ single crystals with $x =$ 0.72 and 0.26. The DC and AC magnetic susceptibilities display anomalies with characteristic of the…
By means of magnetic, specific heat and pyroelectric measurements, we report on magnetic ferroelectricity in the quadruple perovskite \namno, characterized by a canted antiferromagnetic (AFM) CE structure. Surprisingly, ferroelectricity is…
The number of magnetoelectric multiferroic materials reported to date is scarce, as magnetic structures that break inversion symmetry and induce an improper ferroelectric polarization typically arise through subtle competition between…
We present the microscopic theory of improper multiferroicity in BiMnO3, which can be summarized as follows: (1) the ferroelectric polarization is driven by the hidden antiferromagnetic order in the otherwise centrosymmetric C2/c structure;…