Biquadratic interactions and spin-Peierls transition in the spin-1 chain LiVGe2O6

Authors
Millet, P Mila, F Zhang, FC Mambrini, M Van Oosten, AB Pashchenko, VA Sulpice, A Stepanov, A
Citation
P. Millet et al., Biquadratic interactions and spin-Peierls transition in the spin-1 chain LiVGe2O6, PHYS REV L, 83(20), 1999, pp. 4176-4179
Citations number
19
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW LETTERS
ISSN journal
00319007 → ACNP
Volume
83
Issue
20
Year of publication
1999
Pages
4176 - 4179
Database
ISI
SICI code
0031-9007(19991115)83:20<4176:BIASTI>2.0.ZU;2-Z
Abstract
The magnetic susceptibility of a new one-dimensional S = 1 system, the vana dium 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, an d it is consistent with a gapless spectrum above this temperature. We propo se that this behavior is due to the presence of a significant biquadratic e xchange interaction, a suggestion supported by quantum chemistry calculatio ns that take into account the quasidegeneracy of the t(2g) levels.