Multiferroicity in the geometrically frustrated FeTe2O5Cl

Abstract

The layered FeTe2O5Cl compound was studied by specific-heat, muon spin relaxation, nuclear magnetic resonance, dielectric, as well as neutron and synchrotron x-ray diffraction measurements, and the results were compared to isostructural FeTe2O5Br. We find that the low-temperature ordered state, similarly as in FeTe2O5Br, is multiferroic -the elliptical amplitude-modulated magnetic cycloid and the electric polarization simultaneously develop below 11 K. However, compared to FeTe2O5Br, the magnetic elliptical envelop rotates by 75(4)• and the orientation of the electric polarization is much more sensitive to the applied electric field. We propose that the observed differences between the two isostructural compounds arise from geometric frustration, which enhances the effects of otherwise subtle Fe 3+ (S = 5/2) magnetic anisotropies. Finally, x-ray diffraction results imply that, on the microscopic scale, the magnetoelectric coupling is driven by shifts of the O1 atoms, as a response to the polarization of the Te 4+ lone-pair electrons involved in the Fe-O-Te-O-Fe exchange bridges.

Lone-pair self-containment in pyritohedron-shaped closed cavities: optimized hydrothermal synthesis, structure, magnetism and lattice thermal conductivity of Co15F2(TeO3)14

“…Recently, transition-metal halo-tellurites and halo-selenites have been investigated as quantum spin systems with interesting magnetic and physical properties. For example, FeSeO3F 16 is composed of alternating antiferromagnetic chains and FeTe2O5Br exhibits multiferroicity. 16 These oxohalides can be divided into two categories: the larger halide ions (Cl − and Br − ) with low coordination numbers act as a terminal ligands, with examples being FeTe2O5X (X = Cl, Br), 17 Cu2Te2O5X2, 18 Ni5(TeO3)4X2, 12 Cu4Te5O12Cl4 19 and Fe3Te3O10Cl.…”

Spin fluctuations and frustrated magnetism in multiferroicFeVO4

“…2(b), is approximately 8 MHz, which is considerably less than f H and therefore indicates that the hyperfine field on the V sites is almost perpendicular to the applied external field. The NMR spectrum in incommensurate magnetically ordered states usually has a characteristic "doublehorn" feature, [16][17][18] but this is obtained when the applied field is not perpendicular to the internal field. Thus in our present field configuration we are not able to distinguish between an incommensurate spin structure and other forms of modulation that also give rise to a distribution of hyperfine fields, and can state only that our broad line shapes are consistent with the known incommensurate order.…”

Anisotropic spin-flip-induced multiferroic behavior in kagome Cu3Bi(SeO3)2OHc1, Chandrasekhar2, Yuan3 et al. 2017Phys. Rev. BSelf Cite40080View full textAdd to dashboardCite

“…Physical insights into the coupling of the multiferroic property can be assigned to the correlation between the charge, spin, orbital, and lattice degrees of freedom [2]. To date, multiferroic behaviors have been demonstrated in a number of systems with the aid of theoretical calculations, along with the advancement of experimental techniques [3][4][5][6][7]. Several mechanisms such as the Dzyaloshinskii-Moriya (DM) interaction [3], exchange striction, geometric frustration [4,5], and metal-ligand hybridization (p-d interaction) [6,7] have been theoretically established to explain the multiferroic properties.…”

“…To date, multiferroic behaviors have been demonstrated in a number of systems with the aid of theoretical calculations, along with the advancement of experimental techniques [3][4][5][6][7]. Several mechanisms such as the Dzyaloshinskii-Moriya (DM) interaction [3], exchange striction, geometric frustration [4,5], and metal-ligand hybridization (p-d interaction) [6,7] have been theoretically established to explain the multiferroic properties. Geometrical spin frustration systems such as triangular lattice, kagome lattice, pyrochlore lattice, and spinel structure play a major role in condensed matter to achieve diverse physical properties [8][9][10][11][12].…”