Oxalate-mediated long-range antiferromagnetism order in Fe₂(C₂O₄)₃·4H₂O

Abstract

In this paper we reveal for the first time the magnetic properties of iron oxalate tetrahydrate, a compound commercialized for decades but whose structure was solved only recently. Susceptibility measurements and neutron powder diffraction experiments reveal the establishment of a long-range magnetic order below 25 K. The magnetic structure can be described with a propagation vector k = (½, ½, 0). The magnetic ordered phase is characterized by collinear antiferromagnetic couplings between adjacent Fe(3+) atoms, whatever the chelating mode of the oxalate ligand. Moreover, an analysis of the topology reveals that a fourth Fe-Fe magnetic coupling has to be taken into account to generate 3D long range order.

Octahedral Lattice Distortion-Driven Ferroelectricity and Canted Antiferromagnetism in Oxalate and Phenanthrolin Ligand-Based Chain Molecular Magnets [{Fe(Δ)Fe(Λ)}1–x{Cr(Δ)Cr(Λ)}x(ox)2(phen)2]n (x = 0, 0.1, and 0.5)

“…Very few studies have, however, been previously reported in the literature. For example, the molecular compound {[N­( n -C 4 H 9 ) 4 ]­[Mn II Fe III (C 2 O 4 ) 3 ]} n has been investigated using neutron diffraction measurement revealing a two-dimensional AFM ordering, whereas in the case of the commercial oxalate-mediated Fe 2 (C 2 O 4 ) 3 ·4H 2 O compound, a long-range AFM ordering has been established …”

Hybrid Inorganic‐Organic Frameworks: Synthesis and Crystal Structures of RbFe(SO4)(C2O4)0.5·H2O and CsM(SO4)(C2O4)0.5·H2O (M = Mn, Fe)

“…Transition metal oxalates attracted much attention due to their interesting magnetic, electrochemical properties or their ionic conductivity in recent years . The melting point of oxalic acid is relatively low (103.5 °C), and synthesis conditions for novel oxalates are, thus, mild.…”

“…The oxalate anion has an ability to provide either antiferromagnetic or ferromagnetic superexchange pathways due to its wide variety of coordination modes between metal ions . The structures of metal oxalate coordination compounds are variable partly due to its coordination variety so that isolated clusters, 1D chains, 2D layers, or 3D frameworks have been reported …”

“…Transition metal oxalates attracted much attention due to their interesting magnetic, electrochemical properties or their ionic conductivity in recent years. [1][2][3][4][5][6][7][8][9] The melting point of oxalic acid is relatively low (103.5°C), and synthesis conditions for novel oxalates are, thus, mild. The oxalate anion has an ability to provide either antiferromagnetic or ferromagnetic superexchange pathways due to its wide variety of coordination modes between metal ions.…”

“…[10] The structures of metal oxalate coordination compounds are variable partly due to its coordination variety so that isolated clusters, 1D chains, 2D layers, or 3D frameworks have been reported. [2][3][4][5][6][7][8][9][10][11][12] Moreover homeleptic and heteroleptic oxalate complexes have been reported as well as complexes with two or more coordinated metal ions, giving rise to a plethora of compounds.…”