Exploring magnetism, topology, and magnetoresistance in rare-earth-based compound GdAuSn: <i>Ab initio</i> study

Rare-earth intermetallics, especially Gd-based compounds, are of great interest due to their diverse magnetic ground states and intriguing topological properties. Using first-principles calculations, we investigate the magnetic, electronic, and phononic properties of GdAuSn. Our results identify the C-type antiferromagnetic configuration as the lowest energy state, with a critical temperature of 25 K estimated using the Heisenberg spin model and mean-field approximation. The electronic band structure reveals nodal surfaces and Dirac points, highlighting the material’s non-trivial topology. In the magnetically ordered state, GdAuSn exhibits positive transverse magnetoresistance, increasing to ∼25% at 3.5 T and 10 K, with Hall resistivity analysis confirming electron-dominated transport. Additionally, phonon dispersion analysis uncovers topological phononic states with nodal surfaces. These findings provide insights into the interplay of magnetism, topology, and transport in GdAuSn, establishing its potential for fundamental research and topological antiferromagnetic spintronics.