Coexistence of long-range magnetic order and dynamical magnetism in the V-based Kagome metals: A combined thermodynamic and $\mu$SR study

TL;DR

This study reveals that V-based Kagome metals exhibit both long-range magnetic order and persistent spin fluctuations at very low temperatures, highlighting complex magnetic ground states influenced by rare-earth elements.

Contribution

It provides the first combined thermodynamic and $bc$SR analysis showing coexistence of static and dynamic magnetism in V-based Kagome metals, emphasizing the role of 4$f$-electron anisotropy.

Findings

Magnetic phase transitions occur below 4 K in all compounds.

Persistent spin fluctuations are observed down to 50 mK.

Distinct magnetic behavior compared to Mn-based analogs.

Abstract

V-based Kagome metals exhibit a unique lattice geometry that can give rise to exotic electronic and magnetic phenomena, making them an ideal platform to study the interplay of topology and magnetism. We present a combined thermodynamic and muon spin relaxation ($\mu$SR) investigation of single-crystal RV$_{6}$Sn$_{6}$ (R = Tb, Dy, Ho, Er) compounds, focusing on their low-temperature magnetic behavior. Heat capacity and $\mu$SR measurements reveal distinct magnetic phase transitions below 4 K, confirming the emergence of long-range magnetic order in all compounds studied. The $\mu$SR results further indicate persistent spin fluctuations within the magnetically ordered state down to 50 mK, reflected in reduced ordered moments obtained from hyperfine analysis of the heat capacity measurements. These findings uncover the coexistence of static and dynamic magnetism in V-based Kagome metals and emphasizing the key role of 4$f$-electron anisotropy in shaping their magnetic ground states. Compared with the Mn-based RMn$_{6}$Sn$_{6}$ analogs, our results highlight the unique magnetism arising from the decoupled rare-earth sublattice and its interplay with the nonmagnetic V Kagome network.