YbV${}_3$Sb${}_4$ and EuV${}_3$Sb${}_4$, vanadium-based kagome metals with Yb${}^{2+}$ and Eu${}^{2+}$ zig-zag chains

Here we present YbV${}_3$Sb${}_4$ and EuV${}_3$Sb${}_4$, two new compounds exhibiting slightly distorted vanadium-based kagome nets interleaved with zig-zag chains of divalent Yb${}^{2+}$ and Eu${}^{2+}$ ions. Single crystal growth methods are reported alongside magnetic, electronic, and thermodynamic measurements. YbV${}_3$Sb${}_4$ is a nonmagnetic metal with no collective phase transitions observed between 60mK and 300K. Conversely, EuV${}_3$Sb${}_4$ is a magnetic kagome metal exhibiting easy-plane ferromagnetic-like order below $T_{\text{C}}$=32K with signatures of noncollinearity under low field. Our discovery of YbV${}_3$Sb${}_4$ and EuV${}_3$Sb${}_4$ demonstrate another direction for the discovery and development of vanadium-based kagome metals while incorporating the chemical and magnetic degrees of freedom offered by a rare-earth sublattice.