Evolution of Highly Anisotropic Magnetism in the Titanium-Based Kagome Metals LnTi<sub>3</sub>Bi<sub>4</sub> (Ln: La···Gd<sup>3+</sup>, Eu<sup>2+</sup>, Yb<sup>2+</sup>)
Brenden R. Ortiz, Hu Miao, David Parker, Fazhi Yang, German D. Samolyuk, Eleanor M. Clements, Anil Rajapitamahuni, Turgut Yilmaz, E. Vescovo, Jiaqiang Yan, Andrew F. May, Michael A. McGuire
Abstract
Here, we present a family of titanium-based kagome metals of the form LnTi 3 Bi 4 (Ln: La···Gd 3+, Eu 2+, Yb 2+ ). Four previously unreported compounds are presented: YbTi 3 Bi 4, GdTi 3 Bi 4, NdTi 3 Bi 4, and PrTi 3 Bi 4 . Single-crystal growth methods are provided alongside detailed magnetic and thermodynamic measurements across the entire series. The LnTi 3 Bi 4 family of compounds are orthorhombic ( Fmmm ), layered compounds that exhibit slightly distorted titanium-based kagome nets interwoven with zigzag 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 zigzag 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. The combination of the kagome-based electronic structure and highly anisotropic Ln-based magnetism on an exfoliatable platform cements the LnTi 3 Bi 4 family as an interesting addition to the ever-expanding suite of kagome metals.