Scaling investigation of anomalous Hall resistivity in ferrimagnetic D 0 ₂₂ -phase Mn 2.8+x Ga 1.2-x (x = 0.0 – 0.4) alloy

Mn3Ga is an important material in magnetism and spintronics due to its distinct properties of low magnetic moment, high spin-polarization, strong perpendicular magnetic anisotropy, excellent thermal stability, etc., making it suitable for next-generation memory technologies and energy-efficient nanoscale electronic devices. In this work, we report a systematic study of the structural, magnetic, and magnetotransport properties of Mn2.8+xGa1.2-x (x = 0-0.4) alloys to elucidate the interplay among composition, magnetism, and charge transport. Structural analysis confirms the formation of the tetragonal D022-phase for compositions with x > 0.1. Magnetic measurements reveal ferrimagnetic behavior, with a maximum saturation magnetization of 26.80 emu/g for x = 0.2 and a coercivity of 6.55 kOe for x = 0.3. Longitudinal resistivity measurements indicate metallic conduction, led by electron-magnon scattering at low temperatures, while both electron-magnon and electron-phonon scatterings occur at higher temperatures. A pronounced Hall resistivity is observed across all compositions, reaching a maximum value of 0.99 ± 0.02 μΩ-cm for x = 0.3. Scaling investigation of the anomalous Hall resistivity denotes that the effect arises from either extrinsic side-jump mechanisms or intrinsic contributions associated with Berry curvature. These results provide valuable insights into the relationship between crystal structure, magnetic interactions, and transport properties in the D022-phase of Mn3Ga-based alloys.