Magnetic transitions in the chiral armchair-kagome system Mn2Sb2O7

Abstract

The competition between interactions in frustrated magnets allows a wide variety of new ground states, often exhibiting emergent physics and unique excitations. Expanding the suite of lattices available for study enhances our chances of finding exotic physics. Mn2Sb2O7 forms in a chiral, kagome-based structure in which a fourth member is added to the kagome-plane triangles to form an armchair unit and link adjacent kagome planes. This structural motif may be viewed as intermediate between the triangles of the kagome network and the tetrahedra in the pyrochlore lattice. Mn2Sb2O7 exhibits two distinct magnetic phase transitions, at 11.1 and 14.2 K, at least one of which has a weak ferromagnetic component. The magnetic propagation vector does not change through the lower transition, suggesting a metamagnetic transition or a transition involving a multi-component order parameter. Although previously reported in the P 3121 space group, Mn2Sb2O7 actually crystallizes in P 2, which allows ferroelectricity, and we show clear evidence of magnetoelectric coupling indicative of multiferroic order. The quasi-two-dimensional 'armchair-kagome' lattice presents a promising platform for probing chiral magnetism and the effect of dimensionality in highly frustrated systems.

Frustrated antiferromagnetic honeycomb-tunnel-like latticeCuR2Ge2O8(R=Pr, Nd, S

“…It implies that the sign of exchange interaction along each path is expected to be different as well [41]. Such a complicated mixture of competing interactions is most likely to be a leading factor to make this system frustrated [42][43][44][45].…”

3d -electron Heisenberg pyrochlore Mn2Sb2O7Peets1, Sim2, Avdeev3 et al. 2016Phys. Rev. BSelf Cite9060View full textAdd to dashboardCite

“…Pyrochlore FeF 3 orders magnetically at 22 K [11,17], a more than 10-fold suppression relative to its less-symmetric and lessfrustrated rhombohedral polymorph[18], while the 2.7 K transition in NaSrMn 2 F 7 also indicates very strong frustration. Curiously, pyr-Mn 2 Sb 2 O 7 has been reported to form a spin glass around 41 K [14,15], several times higher than the magnetic transition in its less-frustrated P 3 1 21 polymorph [12,19][20]. With pyr-Mn 2 Sb 2 O 7 having a Curie-Weiss temperature just under 50 K, its putative 41 K transition would correspond to remarkably low frustration in the most-frustrated known three-dimensional magnetic lattice.In a Heisenberg pyrochlore, the most likely magnetic ground state would be a counterpart of the all-in-allout state found in Ising pyrochlore antiferromagnets, but the considerable degeneracy could make a variety of other states possible [8], or may prevent long-range order [21,22].…”

“…The Mn 2+ magnetic ion adopts a 3d 5 high-spin electronic configuration, with no orbital degree of freedom, leaving the spin directions fully unconstrained. The magnetic behavior is strikingly similar to that in several closely-related 3d pyrochlores having unquenched orbital moments, indicating that the low spin-orbit coupling in the 3d transition metals may render a much broader family of materials as effective Heisenberg pyrochlore systems.When prepared by conventional solid-state synthesis, Mn 2 Sb 2 O 7 forms in a distorted, chiral variant of the trigonal Weberite structure [19,23,24], but the desired py-arXiv:1611.02811v1 [cond-mat.str-el]…”

“…When prepared by conventional solid-state synthesis, Mn 2 Sb 2 O 7 forms in a distorted, chiral variant of the trigonal Weberite structure [19,23,24], but the desired py-arXiv:1611.02811v1 [cond-mat.str-el]…”

“…When prepared by conventional solid-state synthesis, Mn 2 Sb 2 O 7 forms in a distorted, chiral variant of the trigonal Weberite structure [19,23,24], but the desired py-arXiv:1611.02811v1 [cond-mat.str-el] 9 Nov 2016 rochlore polymorph ( Fig. 1a inset) can be stabilized at lower temperatures [13][14][15].…”