Infrared study of spin-Peierls compound alpha'-NaV2O5

TL;DR

This study uses infrared spectroscopy to analyze the phonon modes, magnetic excitations, and structural fluctuations in the spin-Peierls compound alpha'-NaV2O5, revealing anisotropic absorption features and pretransitional phenomena.

Contribution

It provides new insights into the lattice dynamics and magnetic excitations of alpha'-NaV2O5 through detailed infrared spectral analysis.

Findings

Identification of phonon modes and magnetic excitation continuum.

Observation of anisotropic near-IR absorption at 0.8 eV.

Detection of pretransitional structural fluctuations up to 65K.

Abstract

Infrared reflectance of alpha'-NaV2O5 single crystals in the frequency range from 50 cm-1 to 10000 cm-1 was studied for a, b and c-polarisations. In addition to phonon modes identification, for the a-polarised spectrum a broad continuum absorption in the range of 1D magnetic excitation energies was found. The strong near-IR absorption band at 0.8 eV shows a strong anisotropy with vanishing intensity in c-polarisation. Activation of new phonons due to the lattice dimerisation were detected below 35K as well as pretransitional structural fluctuations up to 65K.