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Study of spin-Peierls transition in alpha'--NaV2O5 by infrared reflectivity

D. Smirnov·P. Millet·J. Leotin·D. Poilblanc·J. Riera·D. Augier·P. Hansen
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Abstract

Polarized infrared reflectivity measurements have been performed on single crystals of the spin-Peierls compound alpha'-NaV2O5 in the temperature range 20-300 K. Pronounced spectral features associated with the formation of the dimerized phase were detected both in the a- and b-polarizations (perpendicular and parallel to the spin-1/2 chains, respectively). The temperature dependence of a salient spectral line at 718 cm^-1 sharply rising below the transition temperature T_SP obeys a (1-T/T_SP)^(2beta) law with T_SP \simeq 34.3$K and beta \simeq 0.25. In addition, a continuum signal is observed in the whole temperature range in the a-polarized optical conductivity spectra. In order to interpret these results, calculations of the static dimerization and of the optical conductivity based on a mean-field and a dynamical treatment of the lattice respectively are proposed.

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D. Smirnov, P. Millet, J. Leotin, D. Poilblanc, J. Riera, D. Augier, P. Hansen. 1998-05-14. Study of spin-Peierls transition in alpha'--NaV2O5 by infrared reflectivity. https://doi.org/10.1103/physrevb.57.r11035

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