Tuning charge density wave of kagome metal ScV6Sn6

TL;DR

This study explores how chemical substitution and pressure influence the charge density wave transition in kagome metal ScV6Sn6, revealing phonon and multi-carrier effects on its electrical properties and anomalous Hall behavior.

Contribution

It demonstrates how Cr substitution and pressure shift the CDW transition and affect electrical responses, highlighting phonon and multi-carrier effects in ScV6Sn6.

Findings

CDW transition shifts from 92 K to 50 K under substitution and pressure

Resistivity responses differ under stimuli, with quadratic MR after Cr substitution

Persistent anomalous Hall-like behavior up to CDW transition

Abstract

Compounds with a kagome lattice exhibit intriguing properties and the charge density wave (CDW) adds an additional layer of interest to research on them. In this study, we investigate the temperature and magnetic field dependent electrical properties under a chemical substitution and hydrostatic pressure of ScV6Sn6, a non-magnetic charge density wave (CDW) compound. Substituting 5 % Cr at the V site or applying 1.5 GPa of pressure shifts the CDW to 50 K from 92 K. This shift is attributed to the movement of the imaginary phonon band, as revealed by the phonon dispersion relation. The longitudinal and Hall resistivities respond differently under these stimuli. The magnetoresistance (MR) maintains its quasilinear behavior under pressure, but it becomes quadratic after Cr substitution. The anomalous Hall-like behavior of the parent compound persists up to the respective CDW transition under pressure, after which it sharply declines. In contrast, the longitudinal and Hall resistivities of Cr substituted compounds follow a two-band model and originates from the multi carrier effect. These results clearly highlight the role of phonon contributions in the CDW transition and call for further investigation into the origin of the anomalous Hall-like behavior in the parent compound.