Lattice dynamics of CuGeO$_3$ : inelastic neutron scattering and model calculations

TL;DR

This study combines inelastic neutron scattering and model calculations to analyze the lattice dynamics of CuGeO₃, revealing detailed dispersion curves and explaining the structural distortion in the spin-Peierls phase.

Contribution

It provides a comprehensive set of dispersion curves and explains the propagation vector of the structural distortion in CuGeO₃ using combined experimental and theoretical methods.

Findings

Dispersion curves along three orthorhombic directions and [101] are nearly complete.

The dispersion of modes involved in the spin-Peierls transition explains the structural distortion propagation.

The study links lattice dynamics to the spin-Peierls transition mechanism.

Abstract

The lattice dynamics in CuGeO$_3$ has been analyzed by the combination of inelastic neutron scattering studies and lattice dynamical model calculations. We report an almost complete set of dispersion curves along the three orthorhombic directions and along [101]. The dispersion of branches associated with the modes directly involved in the spin-Peierls transition allows to explain the particular propagation vector of the structural distortion in the dimerized phase.