Search for soft lattice modes in the magnetic kagome metal YbFe6Ge6

Due to magnetism, topological properties, electron correlations and their interplay, magnetic kagome materials are attracting attention as a platform to explore exotic quantum phases [1]. Recent studies on the correlated kagome magnet FeGe [2] exemplify this interplay-driven phenomenon, revealing an unprecedented CDW order, whose dynamics unveils an intriguing dimerization driven order-disorder scenario [3]. Similar to the 166 ScV6Sn6 compound demonstrated a soft lattice dynamics [4], YbFe6Ge6 hosts 2 kagome planes per unit cell and features the same magnetic order as FeGe. In this proposal, we aim at investigating the lattice dynamics of the antiferromanetic YbFe6Ge6 by means of diffuse and inelastic x-ray scattering (IXS) and search for diffuse signals, characteristic of pre-transitional fluctuations of soft modes. We intend to comprehensively measure the temperature and momentum dependence of the low energy acoustic and optical phonons by means of high-resolution IXS.