Eur. Phys. J. B 23, 427-435 (2001)
https://doi.org/10.1007/s100510170033

Infrared spectra and lattice vibrations of the spin-chain compound LiCuVO₄

¹ Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
² Faculty of Physics, Rostov State University, Zorge Str. 5, 344090 Rostov-on-Don, Russia
³ Physikalisches Institut, Universität Frankfurt, Robert-Mayer-Str. 2-4, 60054 Frankfurt a.M., Germany

Corresponding author: ^a dressel@pi1.physik.uni-stuttgart.de

Received: 19 February 2001
Revised: 26 June 2001
Published online: 15 October 2001

Abstract

The infrared spectra of the one-dimensional antiferromagnet LiCuVO₄ are measured in the frequency range from 10 cm^-1 to 10 000 cm^-1 and at temperatures from 2 K to 300 K, for the electric field vector E of the radiation polarized either along the a- or along the b-crystallographic directions. For each polarization six infrared active phonon modes are observed in accordance with factor group analysis of the crystal structure of LiCuVO₄. The theoretical group analysis of the possible spinel low-symmetry phases is performed within the framework of Landau's theory of phase transitions. The parameters of several phonon lines show noticeable anomalies around 150 K where the magnetic correlations appear in the copper chains, which may indicate a finite interaction between the phonon and the magnon subsystems in LiCuVO₄.