Neutron scattering andμSR investigations of quasi-one-dimensional magnetism in the spin=3/2compound Li3

Abstract

The S=3/2, quasi-1D zig-zag chain Heisenberg antiferromagnet Li 3 RuO 4 has been investigated using inelastic neutron scattering, neutron diffraction and μSR measurements on a powder sample. Our neutron diffraction and μSR studies confirm a long-range ordering of the magnetic moments on the Ru 5+ cations below 40 K. The magnetic excitations were measured at various temperatures above and below the three-dimensional (3D) ordering temperature in order to understand the broad peak observed in the temperature dependence of the magnetic susceptibility.At 5 K we have observed two well-defined magnetic excitations at 5.5 meV and 8.5 meV, and a weak low-energy peak near ~2 meV. We interpret the 5.5 meV energy peak as a 1D zone boundary mode and that at 8.5 meV as arising from a maximum away from the zone-boundary in the dispersion curve for spin-wave modes along the chain of Ru 5+ ions. The weaker peak near 2 meV is thought to arise from a weak inter-chain coupling. Our data are best reproduced using a model with three intrachain interactions and one weak interchain interaction. The experimental spin-exchange interactions are in good agreement with those calculated for a 1D model by DFT methods. Furthermore, above T N we observe strong diffuse scattering at the same Q-position as 2 the 5.5 meV mode, which suggests the presence of short-range magnetic correlations above T N .We have estimated the correlation length, ξ ~2.9 Å at 50 K, which is close to 2.99 Å, the shortest distance between the Ru 5+ cations along the zig-zag chain.

Characterization of magnetic properties ofSr2CuWO6andSr2Vasala1, Saadaoui2, Morenzoni3 et al. 2014Phys. Rev. B

“…In our case the NPD data did not show any magnetic reflections for Sr 2 CuWO 6 , and thus the type of the magnetic order could not be verified. This is not surprising, as quasi-low-dimensional systems often exhibit weak magnetic reflections, even when they are magnetically ordered [33,34]. In the case of Ba 2 CuWO 6 , early NPD studies could not find magnetic reflections either [10].…”

Antiferromagnetism atT>500Kin the layered hexagonal ruthenateSrRu2O6Hiley1, Scanlon2, Sokol3 et al. 2015Phys. Rev. BSelf Cite503340View full textAdd to dashboardCite

“…Figure 4 and Table I shows the results of Rietveld refinement of atomic and magnetic structure refinements against powder neutron diffraction data at temperature above and below the magnetic ordering temperature. The atomic structure is refined using the expected P3 ̅ 1m spacegroup for the PbSb 2 O 6 structure, with no evidence for any structural phase transition over the temperature range studied, while the magnetic structure was solved using P3 ̅ 1c spacegroup, revealing an arrangement of spins such that there is antiferromagnetic order both within and between layers, Figure 5a inset, analogous to G-type order in cubic unit cell (hexagonal type II, according to the classification by Goodenough [20] [14,17], which may be ascribed to some degree of covalency in M-O bonds in 4d metal oxides [35]. The evolution of the ordered moment as a function of temperature,…”

“…While some strontium ruthenates contain Ru in the +5 or the +6 oxidation state, for example Sr 2 [9] and Sr 4 Ru 2 V Ru VI O 12 [10], their magnetic properties have been less explored, despite the interesting phenomena observed in other Ru(V)-containing oxides [11][12][13][14][15][16][17]. The interest in ruthenates is part of a wider focus on the magnetism of 4d and 5d oxides, which differ considerably from the more widely studied 3d oxides when effects such as strong spin-orbit coupling are considered [18].…”

Spin wave excitations in the pyrovanadate α−Cu2V2O7

“…4(c)). There are several reasons for line-width broadening, such as (i) magnon-electron (ii) magnon-magnon or (iii) magnon-phonon interactions, 17 which are not considered in our simulation. α-Cu 2 V 2 O 7 being a very good insulator, magnon-electron scattering can be neglected.…”