Intricate Magnetic Landscape in Antiferromagnetic Kagome Metal TbTi<sub>3</sub>Bi<sub>4</sub> and Interplay with Ln<sub>2–<i>x</i></sub>Ti<sub>6+<i>x</i></sub>Bi<sub>9</sub> (Ln: Tb···Lu) Shurikagome Metals
Brenden R. Ortiz, Heda Zhang, Karolina Górnicka, David Parker, German D. Samolyuk, Fazhi Yang, Hu Miao, Qiangsheng Lu, R. G. Moore, Andrew F. May, Michael A. McGuire
Abstract
Here we present the discovery and characterization of the kagome metal TbTi 3 Bi 4 in tandem with a new series of compounds, the Ln 2 – x Ti 6+ x Bi 9 (Ln: Tb–Lu) shurikagome metals. We previously reported on the growth of the LnTi 3 Bi 4 (Ln: La–Gd 3+, Eu 2+, Yb 2+ ) family, a chemically diverse and exfoliable series of kagome metals with complex and highly anisotropic magnetism. However, unlike the La–Gd analogs, TbTi 3 Bi 4 cannot be synthesized by our previous methodology due to phase competition with crystals of Ln 2 – x Ti 6+ x Bi 9 ( x ∼ 1.7–1.2). Here we discuss the phase competition between the LnTi 3 Bi 4 and Ln 2 – x Ti 6+ x Bi 9 families, helping to frame the difficulty in synthesizing LnTi 3 Bi 4 compounds with small Ln species and providing a strategy to circumvent the formation of Ln 2 – x Ti 6+ x Bi 9 . Detailed characterization of the magnetic and electronic transport properties on single crystals of TbTi 3 Bi 4 reveals a highly complex landscape of magnetic phases arising from an antiferromagnetic ground state. A series of metamagnetic transitions creates at least 5 unique magnetic phase pockets, including a 1/3 and 2/3 magnetization plateau. Further, the system exhibits an intimate connection between the magnetism and magnetotransport, exhibiting sharp switching from positive (+40%) to negative magnetoresistance (−50%). Like the LnTi 3 Bi 4 kagome metals, the Ln 2 – x Ti 6+ x Bi 9 family exhibits quasi-2D networks of titanium and chains of rare earth. We present the structures and some basic magnetic properties of the Ln 2 – x Ti 6+ x Bi 9 family alongside our characterization of the newly discovered TbTi 3 Bi 4 .