  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.
