Magnetic excitations in the orbitally degenerate triangular lattice LiVO2

We report an inelastic-neutron scattering study of the magnetic excitations in LiVO2, a two-dimensional triangular lattice of V3+ (S = 1) ions with orbital ordering involving threefold degenerate t(2g) orbitals. At temperatures well below the phase transition temperature T-t approximate to 500 K, an excitation at similar to 58meV is observed which we identify as a candidate for the principal singlet-to-triplet magnetic transition. Additional excitations are also observed at lower and higher energies. Our results suggest that orbital degeneracy plays an important role in understanding the unusual magnetic properties of LiVO2. (c) 2006 Elsevier B.V. All rights reserved.