Exploring antiferromagnetic spintronics within intermetallic NiSi system*

Antiferromagnetic materials hold potential for spintronic applications due to their robustness, lack of stray fields, fast dynamics, and significant magnetotransport properties. Ongoing research on unconventional antiferromagnets like Mn₃Si, FeGe, Mn₂Au, etc., has made them promising candidates for spin-based applications. Our recent efforts to grow a single crystal of the stoichiometric Nickel silicon system have successfully showcased magnetic order for the first time. Extensive neutron diffraction measurements have revealed non-trivial temperature dependences of nuclear as well as odd reciprocal lattice positions, indicating the existence of an uncompensated antiferromagnetic order with an onset temperature T_N = 700 K in the system. This system is further observed to exhibit hysteresis behavior with one-step switching characteristics at a very small critical field of H ~ 900 Oe applied perpendicular to the direction of non-compensated (ferromagnetic) moments accounting for the switching between two distinct ferromagnetic spin configurations. Hall probe measurements unveil intricate magneto-electronic hysteresis in both longitudinal and Hall resistance at high temperatures, demonstrating unique antiferromagnetic spin correlation distinct from magnetometry results. These characteristics emphasize the significance of NiSi in propelling antiferromagnetic spintronics research.