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

P. Millet·F. Mila·F. C. Zhang·M. Mambrini·A. B. Van Oosten·V. A. Pashchenko·A. Sulpice·A. Stepanov
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Abstract

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.

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P. Millet, F. Mila, F. C. Zhang, M. Mambrini, A. B. Van Oosten, V. A. Pashchenko, A. Sulpice, A. Stepanov. 1999-09-24. Biquadratic interactions and spin-Peierls transition in the spin 1 chain LiVGe2O6. https://doi.org/10.1103/physrevlett.83.4176

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