相关论文: Magnetic inversion symmetry breaking and ferroelec…
Magnetic structure evolution of multiferroic hexagonal $YMn_{1-x}Fe_{x}O_{3}$ (${x} = 0, 0.05,$ and $0.1$) has been studied by carrying out detailed temperature-dependent neutron diffraction at zero- and 5T-fields. Thermodynamic data…
The triangular spin lattice of NiBr$_{2}$ is a canonical example of a frustrated helimagnet that shows a temperature-driven phase transition from a collinear commensurate antiferromagnetic structure to an incommensurate spin helix on…
Temperature-dependent x-ray diffraction of the low-dimensional spin 1/2 quantum magnet TiOBr shows that the phase transition at T_{c2} = 47.1 (4) K corresponds to the development of an incommensurate superstructure. Below T_{c1} = 26.8 \pm…
Using single crystal neutron scattering we show that the magnetic structure Ni$_3$TeO$_6$ at fields above 8.6 T along the $c$ axis changes from a commensurate collinear antiferromagnetic structure with spins along c and ordering vector…
Using in-field single crystal neutron diffraction we have determined the magnetic structure of TbMnO3 in the high field P||a phase. We unambiguously establish that the ferroelectric polarization arises from a cycloidal Mn spins ordering,…
The structural phase transition in hexagonal BaMnO$_3$ occurring at $T_c$=130 K was studied in ceramic samples using electron and X-ray diffraction, second harmonic generation as well as by dielectric and lattice dynamic spectroscopies. The…
The complete irreducible co-representations of the paramagnetic space group provide a simple and direct path to explore the symmetry restrictions of magnetically driven ferroelectricity. The method consists of a straightforward…
The (H,T)-phase diagram of the multiferroic perovskite TbMnO$_3$ was studied by high-resolution thermal expansion $\alpha(T)$ and magnetostriction $\Delta L(H)/L$ measurements. Below $T_{N}\simeq 42$ K, TbMnO$_3$ shows antiferromagnetic…
The improper ferroelectricity in YMnO$_3$ and other related multiferroic hexagonal manganites are known to cause topologically protected ferroelectric domains that give rise to rich and diverse physical phenomena. The local structure and…
Ferroelectric spiral magnets DyMnO3 and TbMnO3 show similar behavior of electric polarization in applied magnetic fields. Studies of the field dependence of lattice modulations on the contrary show a completely different picture. Whereas in…
We have identified, for the first time, the change in symmetry at the ferroelectric transition TFE near 1023K of the ferroelectromagnet YMnO3. This transition takes place 300K below the transition to the centrosymmetric state at TIP. Single…
We report a detailed high-resolution powder neutron diffraction investigation of the structural behaviour of the multiferroic hexagonal polymorph of YMnO3 between room temperature and 1403 K. The study was aimed at resolving previous…
The spin ordering of La3/2Sr1/2NiO4 was investigated by magnetization measurements, and by unpolarized- and polarized-neutron diffraction. Spin ordering with an incommensurability epsilon ~ 0.445 is observed below T_so ~ 80 K. On cooling, a…
By combining neutron four-circle diffraction and polarized neutron diffraction techniques we have determined the complex spin structures of a multiferroic, YMn2O5, that exhibits two ferroelectric phases at low temperatures. The obtained…
Hexagonal HoMnO$_{3}$ is a frustrated antiferromagnet (T$_{N}$=72 K) ferroelectric (T$_{C}$=875 K) in which these two order parameters are coupled. Our neutron measurements of the spin wave dispersion for the S=2 Mn$^{3+}$ on the layered…
The interaction of light in terahertz frequency region with electromagnons in a sinusoidal incommensurate magnetic state in TbMnO3 is studied. A significant change in the frequency dependence of the dielectric constant e_zz near the…
Magnetic ordering in TbMnO3 was revisited by a neutron diffraction study. In addition to the previously reported A-type and G-type modulated structures with a propagation vector (0,q_Mn,0), we found C-type and F-type orderings of the Mn…
The electronic and magnetic properties of TbMnO3 leading to its ferroelectric (FE) polarization were investigated on the basis of relativistic density functional theory (DFT) calculations. In agreement with experiment, we show that the…
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 argue that the homogeneous distribution of spins in the spin-spiral state of orthorhombic manganites is deformed by the relativistic spin-orbit interaction. The thus induced spin-spiral inhomogeneity gives rise to the ferroelectric…