Orbital and Spin Chains inZnV2O4

Abstract

Our powder inelastic neutron scattering data indicate that ZnV2O4 is a system of spin chains that are three-dimensionally tangled in the cubic phase above 50 K due to randomly occupied t(2g) orbitals of V3+ (3d(2)) ions. Below 50 K in the tetragonal phase, the chains become straight due to antiferro-orbital ordering. This is evidenced by the characteristic wave vector dependence of the magnetic structure factor that changes from symmetric to asymmetric at the cubic-to-tetragonal transition.

Evolution of the magnetic and structural properties ofFe1−xCoxV2O4

“…Furthermore, the AV 2 O 4 normal spinels can be divided into two groups based on the A ions. One group includes AV 2 O 4 (A = Cd [2][3][4], Mg [5][6][7][8][9], Zn [10,11]) with non-magnetic A ions. In these three materials, the orbital ordering (OO) transition drives a cubic to tetragonal structural phase transition at low temperatures which relieves the geometrical frustration of the Vpyrochlore sublattice and leads to an antiferromagnetic transition of the V 3+ ions.…”

Spin–lattice instability to a fractional magnetization state in the spinel HgCr2O4

“…Several different mechanisms to reduce frustration in the absence of an external magnetic field have been studied 11,[13][14][15][16][17][18][19][20][21][22] with Fddd symmetry at 6 K. 13 Elastic magnetic neutron scattering data obtained with 4 zero field (blue circles in Fig. 1 (a)) shows that in the low temperature phase the spins order long range with two characteristic magnetic wave vectors Q M = (1/2,0,1) and (1,0,0).…”

Néel to spin-glass-like phase transition versus dilution in geometrically frustratedZnCr2−2xGa2xLee1, Ratcliff2, Huang3 et al. 2008Phys. Rev. BSelf Cite

“…The k = (1, 0, 0) domain has a collinear spin structure with spins parallel to the zaxis, as in ZnV 2 O 4 . [29] In each tetrahedron the net spin is zero.…”

“…[27] In comparison, in the case of AV 2 O 4 where the V 2+ (3d 2 ) ion has an orbital degeneracy, a Jahn-Teller distortion can occur at low temperatures, which makes the vanadates effectively one-dimensional spin chain systems. [28,29,30,31] Several novel discoveries have been made in ACr 2 O 4 . For instance, collective excitations of local antiferromagnetic hexagonal spins were found in the spin liquid phase of ZnCr 2 O 4 that embody the zero-energy excitations amongst the degenerate ground states.…”