Alkali Transition‐Metal Molybdates: A Stepwise Approach to Geometrically Frustrated Systems

Abstract

Materials with triangular arrangements of transition metal ions are of great interestf or their complex magnetism resulting from geometric frustration. This paper describes the stepwise formationo fk agomelattices of open shell transition-metal ions from half-delta chains to delta/sawtooth chains, and finally kagomen ets. The systemsc an be viewed as at estbedf or magnetic studies since av ariety of spin states can be introduced across the same structure type, and progress through increasing levels of structuralc omplexity and dimensionality.T he synthetica nd structural development of this continuumi ss tudied here in well-formed single crystals of A 2 M 3 (MoO 4 ) 3 (OH) 2 (A = K, Rb; M = Mn, Co), CsM 2 (MoO 4 ) 2 (OH) (M = Mn, Fe, Co, Zn), and KM 3 (MoO 4 ) 2 O(OH) (M = Mn).[a] Dr.Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Complex magnetic order in the decorated spin-chain system Rb2Mn3(MoO4)3(OH)2Liu1, Sanjeewa2, Garlea3 et al. 2020Phys. Rev. BSelf Cite61160View full textAdd to dashboardCite

“…Rb 2 Mn 3 (MoO 4 ) 3 (OH) 2 single crystals have been grown by the high-temperature high-pressure hydrothermal method 14 . Figure 1(a) shows the picture of a couple of single crystals, which form prismatic dark green crystals with typical sizes of 0.5 × 1.0 × 2.5 mm 3 , with the long edge being closely along the b-axis.…”

“…Table I shows the structural parameters determined from single crystal x-ray diffraction data collected at room temperature, including the atomic coordinates and the displacement parameters. Detailed descriptions of the synthesis and the structure have been published 14 . There are two crystallographically different Mn sites, Mn1 at a 8d position (0.551, 0.498, 0.317), and Mn2 at a 4c Wyckoff position (0.397, 3/4, 0.254), respectively.…”

“…While Rb 2 Fe 2 O(AsO 4 ) 2 has sawteeth on opposite sides of the spin chain, the newly discovered compound Rb 2 Mn 3 (MoO 4 ) 3 (OH) 2 is a bond-alternating chain system 14 , where all the sawteeth of each spin chain are sitting on the same side with no shared magnetic ions between adjacent sawteeth. It looks like a spin chain (Mn1 sites) decorated with magnetic-ion pendants (Mn2 sites) (see Fig.…”

Sodium Transition Metal Vanadates from Hydrothermal Brines: Synthesis and Characterization of NaMn4(VO4)3, Na2Mn3(VO4)3, and Na2Co3(VO4)2(OH)2

“…Such edge shared 2‐D planar systems are of interest because they often display interesting magnetic properties and thus merit a more detailed examination , . We recently observed a topologically similar structure in the alkali transition metal molybdate systems, where KMn 3 (MoO 4 ) 2 O(OH) was found to have an ideal Kagome layer in space group R 3 m . Here, in the related cobalt compound, the pseudo‐Kagome layers are not ideally three‐fold symmetric, having Co–Co distances of 3.008(2) Å and 2.831(2) Å.…”

“…The cobalt oxide layer in 3 is comprised of a hexagonal arrangement of Co–O bonds coordinated to the four nearest hexagons on the top and bottom by a parallelogram of Co–O. An idealized Kagome layer can also be viewed as a series of edge shared delta chains, , of metal‐oxygen octahedra. This arrangement also produces hexagon shapes within the layer.…”