Here we study the stability of charge order in the kagome metal ${\mathrm{ScV}}_6{\mathrm{Sn}}_6$. Synchrotron x-ray diffraction measurements reveal high-temperature, short-range charge correlations at the wave vectors along $\mathbf{q}=(\frac{1}{3},\frac{1}{3},\frac{1}{2})$ whose interlayer correlation lengths diverge upon cooling. At the charge order transition, this divergence is interrupted, and long-range order freezes in along $\mathbf{q}=(\frac{1}{3},\frac{1}{3},\frac{1}{3})$, as previously reported, while disorder enables the charge correlations to persist at the $\mathbf{q}=(\frac{1}{3},\frac{1}{3},\frac{1}{2})$ wave vector down to the lowest temperatures measured. Both short-range and long-range charge correlations seemingly arise from the same instability and both are rapidly quenched upon the introduction of larger Y ions onto the Sc sites. Our results validate the theoretical prediction of the primary lattice instability at $\mathbf{q}=(\frac{1}{3},\frac{1}{3},\frac{1}{2})$, and we present a heuristic picture for viewing the frustration of charge order in this compound.

• Received 19 July 2023
• Accepted 14 September 2023

DOI:https://doi.org/10.1103/PhysRevMaterials.7.104201