Multiple charge density wave transitions in Gd$_2$Te$_5$

TL;DR

This study uncovers two separate charge density wave transitions in Gd$_2$Te$_5$, occurring at different temperatures and involving distinct lattice modulations, with evidence of their coupling.

Contribution

It provides the first detailed experimental observation of multiple CDW transitions and their interaction in Gd$_2$Te$_5$ using advanced diffraction techniques.

Findings

Two CDW transitions at 410 K and 532 K

Distinct on-axis and off-axis lattice modulations

Coupling between the two CDW states

Abstract

Diffraction measurements performed via transmission electron microscopy and high resolution X-ray scattering reveal two distinct charge density wave transitions in Gd$_2$Te$_5$ at $T_{c1}$ = 410(3) and $T_{c2}$ = 532(3) K, associated with the \textit{on}-axis incommensurate lattice modulation and \textit{off}-axis commensurate lattice modulation respectively. Analysis of the temperature dependence of the order parameters indicates a non-vanishing coupling between these two distinct CDW states.