The magnetic susceptibility of a new one-dimensional, S=1 system, the vanadium oxide LiVGe2O6, has been measured. Contrary to previous S=1 chains, it exhibits an abrupt drop at 22 K typical of a spin-Peierls transition, and it is consistent with a gapless spectrum above this temperature. We propose that this behaviour is due to the presence of a significant biquadratic exchange interaction, a suggestion supported by quantum chemistry calculations that take into account the quasi-degeneracy of the t2g levels.
@article{arxiv.cond-mat/9909357,
title = {Biquadratic interactions and spin-Peierls transition in the spin 1 chain LiVGe2O6},
author = {P. Millet and F. Mila and F. C. Zhang and M. Mambrini and A. B. Van Oosten and V. A. Pashchenko and A. Sulpice and A. Stepanov},
journal= {arXiv preprint arXiv:cond-mat/9909357},
year = {2009}
}
Comments
4 pages including 3 figures, to appear in Phys. Rev. Lett