A density-wave-like transition in the polycrystalline V3Sb2 sample with bilayer kagome lattice

TL;DR

This study reports the synthesis and characterization of V3Sb2, a bilayer kagome metal exhibiting a density-wave-like transition at 160 K, with potential topological properties and tunable electronic phases under pressure.

Contribution

It introduces V3Sb2 as a new bilayer kagome compound with a density-wave transition, topological features, and pressure-tunable properties, expanding the understanding of kagome metals.

Findings

Density-wave-like transition at ~160 K with thermal hysteresis

Transition suppressed by ~1.8 GPa pressure, no superconductivity observed

V3Sb2 exhibits non-trivial topological crystalline properties

Abstract

Recently, transition-metal-based kagome metals have aroused much research interest as a novel platform to explore exotic topological quantum phenomena. Here we report on the synthesis, structure, and physical properties of a bilayer kagome lattice compound V3Sb2. The polycrystalline V3Sb2 samples were synthesized by conventional solid-state-reaction method in a sealed quartz tube at temperatures below 850 Celsius degree. Measurements of magnetic susceptibility and resistivity revealed consistently a density-wave-like transition at Tdw ~ 160 K with a large thermal hysteresis, even though some sample-dependent behaviors are observed presumably due to the different preparation conditions. Upon cooling through Tdw, no strong anomaly in lattice parameters and no indication of symmetry lowering were detected in powder x-ray diffraction measurements. This transition can be suppressed completely by applying hydrostatic pressures of about 1.8 GPa, around which no sign of superconductivity is observed down to 1.5 K. Specific-heat measurements reveal a relatively large Sommerfeld coefficient {\gamma} = 18.5 mJ/mol-K2, confirming the metallic ground state with moderate electronic correlations. Density functional theory calculations indicate that V3Sb2 shows a non-trivial topological crystalline property. Thus, our study makes V3Sb2 a new candidate of metallic kagome compound to study the interplay between density-wave-order, nontrivial band topology, and possible superconductivity.