Unearthing new kagome materials; the evolution of highly anisotropic magnetism in LnTi₃Bi₄ kagome metals

Here we present a family of titanium-based kagome metals of the form LnTi₃Bi₄ (Ln: La...Gd³⁺, Eu²⁺, Yb²⁺). Four previously unreported compounds are presented: YbTi₃Bi₄, GdTi₃Bi₄, NdTi₃Bi₄, and PrTi₃Bi₄. We will discuss characterization of single crystals with a focus on detailed magnetic and thermodynamic measurements. The LnTi₃Bi₄ family of compounds are orthorhombic Fmmm, layered compounds that exhibit slightly distorted titanium-based kagome nets interwoven with zig-zag lanthanide-based (Ln) chains. Crystals are easily exfoliated parallel to the kagome sheets and angular resolved photoemission (ARPES) measurements highlight the intricacy of the electronic structure in these compounds. Density functional theory (DFT) and ARPES studies find Dirac points near the Fermi level, consistent with the kagome-derived band structure. The magnetic properties and the associated anisotropy emerge from the quasi-1D zig-zag chains of Ln, and impart a wide array of magnetic ground states ranging from anisotropic ferromagnetism to complex antiferromagnetism with a cascade of metamagnetic transitions. We hope our discussion of these materials can spark new collaborations and directions for exploration in the wider field of magnetic kagome metals.