Extremely large magnetoresistance in single-crystalline ZrBi₂

Magnetoresistance (MR) is a pivotal transport phenomenon within the realm of condensed matter physics. In recent years, materials exhibiting extremely large unsaturated magnetoresistance (XMR), which are often potential topological materials, have garnered significant attention. In this study, we synthesized single crystals of ZrBi₂ and performed electrical and specific heat measurements on them. The resistivity of ZrBi₂ displays metallic behavior with a high residual resistance ratio. Notably, the MR of ZrBi₂ reaches approximately 2.0 × 10³% at 2 K and 16 T without saturation. Weak Shubnikov–de Haas oscillations with two frequencies were observed above 13.5 T, which correspond to 237 T and 663 T. Hall effect fitting yields nearly equal concentrations of electron and hole carriers with concentrations of approximately 10²¹ cm⁻³ and mobilities of approximately 5000 cm²⋅V⁻¹⋅s⁻¹ at 2 K. The XMR could be attributed to the electron–hole compensation with high mobility.