Powder and single crystal neutron diffraction study on Weyl semimetal NdCuGa3

Magnetic topological materials provide an important platform for realizing several exotic quantum phenomena, such as anomalous Hall effect (AHE), anomalous Nernst effect, and skyrmions, owing to the interplay between topology and magnetism. Antiferromagnetic (AFM) materials exhibit AHE due to the presence of nontrivial spin structures. NdCuGa3 crystallizes in a tetragonal structure with an AFM ground state (Néel temperature ~3.4 K). We observed a large AHE of ~1100 Ω-1.cm-1 at 2 K. From magnetic studies, it exhibits AFM to metamagnetic to ferromagnetic transitions under applied magnetic field. Therefore, a knowledge of the ground state and in-field magnetic structures of NdCuGa3 by neutron diffraction is imperative to understand the magnetic phase transitions and origin of large AHE. These promising results suggest the possibility of spintronic devices based on antiferromagnets with tailored noncoplanar AFM to ferromagnetic spin configurations.