The kagom\'e metals RbTi3Bi5 and CsTi3Bi5 were synthesized both as polycrystalline powders by heating the elements an argon atmosphere and as single crystals grown using a self-flux method. The compounds crystallize in the hexagonal crystal system isotypically to KV3Sb5 (P6/mmm, Z = 1, CsTi3Bi5: a = 5.7873(1) {\AA}, c = 9.2062(1) {\AA}; RbTi3Bi5: a = 5.773(1) {\AA}, c = 9.065(1) {\AA}). Titanium atoms form a kagom\'e net with bismuth atoms in the hexagons as well as above and below the triangles. The alkali metal atoms are coordinated by 12 bismuth atoms and form AlB2-like slabs between the kagom\'e layers. Magnetic susceptibility measurements with CsTi3Bi5 and RbTi3Bi5 single crystals reveal Pauli-paramagnetism and traces of superconductivity caused by CsBi2/RbBi2 impurities. Magnetotransport measurements reveal conventional Fermi liquid behavior and quantum oscillations indicative of a single dominant orbit at low temperature. DFT calculations show the characteristic metallic kagom\'e band structure similar to that of CsV3Sb5 with reduced band filling. A symmetry analysis of the band structure does not reveal an obvious and unique signature of a nontrivial topology.
@article{arxiv.2209.11656,
title = {The kagom\'e metals RbTi$_3$Bi$_5$ and CsTi$_3$Bi$_5$},
author = {Dominik Werhahn and Brenden R. Ortiz and Aurland K. Hay and Stephen D. Wilson and Ram Seshadri and Dirk Johrendt},
journal= {arXiv preprint arXiv:2209.11656},
year = {2023}
}