Intricate Magnetic Landscape in Antiferromagnetic\nKagome 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<

Here we present the discovery and\ncharacterization of the kagome\nmetal TbTi<sub>3</sub>Bi<sub>4</sub> in tandem with a new series of\ncompounds, the Ln<sub>2</sub><sub>–</sub><sub><i>x</i></sub>Ti<sub>6+<i>x</i></sub>Bi<sub>9</sub> (Ln: Tb–Lu)\nshurikagome metals. We previously reported on the growth of the LnTi<sub>3</sub>Bi<sub>4</sub> (Ln: La–Gd<sup>3+</sup>, Eu<sup>2+</sup>, Yb<sup>2+</sup>) family, a chemically diverse and exfoliable series\nof kagome metals with complex and highly anisotropic magnetism. However,\nunlike the La–Gd analogs, TbTi<sub>3</sub>Bi<sub>4</sub> cannot\nbe synthesized by our previous methodology due to phase competition\nwith crystals of Ln<sub>2</sub><sub>–</sub><sub><i>x</i></sub>Ti<sub>6+<i>x</i></sub>Bi<sub>9</sub> (<i>x</i> ∼ 1.7–1.2). Here we discuss the phase competition\nbetween the LnTi<sub>3</sub>Bi<sub>4</sub> and Ln<sub>2</sub><sub>–</sub><sub><i>x</i></sub>Ti<sub>6+<i>x</i></sub>Bi<sub>9</sub> families, helping to frame the difficulty in\nsynthesizing LnTi<sub>3</sub>Bi<sub>4</sub> compounds with small Ln\nspecies and providing a strategy to circumvent the formation of Ln<sub>2</sub><sub>–</sub><sub><i>x</i></sub>Ti<sub>6+<i>x</i></sub>Bi<sub>9</sub>. Detailed characterization of the\nmagnetic and electronic transport properties on single crystals of\nTbTi<sub>3</sub>Bi<sub>4</sub> reveals a highly complex landscape\nof magnetic phases arising from an antiferromagnetic ground state.\nA series of metamagnetic transitions creates at least 5 unique magnetic\nphase pockets, including a 1/3 and 2/3 magnetization plateau. Further,\nthe system exhibits an intimate connection between the magnetism and\nmagnetotransport, exhibiting sharp switching from positive (+40%)\nto negative magnetoresistance (−50%). Like the LnTi<sub>3</sub>Bi<sub>4</sub> kagome metals, the Ln<sub>2</sub><sub>–</sub><sub><i>x</i></sub>Ti<sub>6+<i>x</i></sub>Bi<sub>9</sub> family exhibits quasi-2D networks of titanium and chains\nof rare earth. We present the structures and some basic magnetic properties\nof the Ln<sub>2</sub><sub>–</sub><sub><i>x</i></sub>Ti<sub>6+<i>x</i></sub>Bi<sub>9</sub> family alongside\nour characterization of the newly discovered TbTi<sub>3</sub>Bi<sub>4</sub>.