Examination of the Anisotropic Spin Exchange Interactions of CuM2O6 (M=Sb, V, Nb) by Spin Dimer Analysis

Disrupted antiferromagnetism in the branneriteMnV2O6

“…Extended Hückel calculations proposed that the strongest antiferromagnetic interaction is along c, which favors model B for CuV 2 O 6 . 9 The spin arrangement we have determined for MnV 2 O 6 is the same as the model B for CuV 2 O 6 , suggesting that the differences between their short range orderings do not reflect different long range spin ordered ground states.…”

“…8 The exchange interactions were further examined by spin dimer analysis using the extended Hückel method. 9 Heat capacity measurements 10 confirmed the onset of long range order in CuV 2 O 6 to be 22.5 K and Zn doping experiments have shown rapid depression of long range antiferromagnetic order.…”

Torque magnetometry study of magnetically ordered state and spin reorientation in the quasi-one-dimensionalS=12Heisenberg antiferromagnetCuSb2O6Herak1, Žilić2, Čalogović3 et al. 2015Phys. Rev. B9040View full textAdd to dashboardCite

“…Magnetic Cu 2+ ions are treated as spin-only and the effect of their unquenched orbital moment is included in anisotropic electron g tensor. Distorted and usually elongated CuO 6 octahedra found in most copper oxides are responsible for orbital ordering of the 3d orbital of the unpaired electron which then influences the dimensionality of the specific magnetic lattice defined by the dominant interactions between spins S = 1/2 and usually described by the isotropic Heisenberg Hamiltonian H = J ∑ i j S i · S j . In magnetically ordered states, however, magnetic moments choose specific directions in space which are not anticipated by this isotropic model.…”

“…Octahedral oxygen environment of the magnetic Cu 2+ ions gives rise to dominant Cu-O-O-Cu superexchange pathway which forms magnetic chains along the (a + b) direction at z = 0 and (a − b) direction at z = 0.5 [5,6]. Band structure calculations interpreted the origin of one-dimensional magnetism in CuSb 2 O 6 as being driven by unusual orbital ordering which allows superexchange to be realized through d 3z 2 −r 2 orbitals and apical instead of square planar oxygens [7].…”

“…These calculations, however, were performed for tetragonal phase of CuSb 2 O 6 where CuO 6 octahedra are compressed. In monoclinic phase standard orbital ordering of d x 2 −y 2 orbitals is expected due to the above mentioned elongation of octahedra [6].…”