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Infrared signatures of the spin-Peierls transition in CuGeO3

A. Damascelli·D. van der Marel·F. Parmigiani·G. Dhalenne·A. Revcolevschi
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Abstract

We investigated the infrared reflectivity of several Mg- and Si-substituted CuGeO3 single crystals. The temperature dependent b-axis and c-axis optical response is reported. For T<Tsp we detected the activation of zone-boundary phonons along the b axis of the crystal on the pure sample and for 1% Mg and 0.7% Si concentrations. From a detailed analysis of the phonon parameters the redshift of the B2u mode at 48 cm^-1 is observed and discussed in relation to the soft mode expected to drive the spin-Peierls phase transition in CuGeO3. Moreover, the polarization dependence of a magnetic excitation measured in transmission at 44 cm^-1 has been investigated.

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A. Damascelli, D. van der Marel, F. Parmigiani, G. Dhalenne, A. Revcolevschi. 1997-08-04. Infrared signatures of the spin-Peierls transition in CuGeO3. https://doi.org/10.1103/physrevb.56.r11373

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