Tunable magnetism in titanium-based kagome metals by rare-earth engineering and high pressure
Long Chen, Ying Zhou, He Zhang, Xuecong Ji, Ke Liao, Yu Ji, Ying Li, Zhongnan Guo, Xi Shen, Richeng Yu, Xiaohui Yu, Hongming Weng, Gang Wang
Abstract
Abstract Rare-earth engineering is an effective way to introduce and tune magnetism in topological kagome materials, which have been acting as a fertile platform to investigate the quantum interactions between geometry, topology, spin, and correlation. Here, we report the synthesis, structure, and physical properties of titanium-based kagome metals RETi 3 Bi 4 (RE = Yb, Pr, and Nd) with various magnetic states. They all crystallize in the orthogonal space group Fmmm (No. 69), featuring distorted titanium kagome lattices and rare-earth zig-zag chains. By changing the rare earth atoms in the zig-zag chains, the magnetism can be tuned from nonmagnetic YbTi 3 Bi 4 to short-range ordered PrTi 3 Bi 4 ( T anomaly ~ 8.2 K), and finally to ferromagnetic NdTi 3 Bi 4 ( T c ~ 8.5 K). In-situ resistance measurements of NdTi 3 Bi 4 under high pressure further reveal a tunable ferromagnetic ordering temperature. These results highlight RETi 3 Bi 4 as a promising family of kagome metals to explore nontrivial band topology and exotic phases.