Giant anomalous transverse transport properties of Co-doped two-dimensional Fe3GaTe2

In spintronics, transverse anomalous transport properties have emerged as a highly promising avenue surpassing the conventional longitudinal transport behaviors. Here, we explore the transverse transport properties of monolayer and bilayer Fe_3−xCo_xGaTe₂ (x = 0.083, 0.167, 0.250, and 0.330) systems. All the systems exhibit ferromagnetic ground states with metallic features and also have perpendicular magnetic anisotropy. Besides, the magnetic anisotropy is substantially enhanced with increasing Co-doping concentration. However, unlike magnetic anisotropy, the Curie temperature is suppressed by increasing the Co-doping concentration. For instance, the monolayer and bilayer Fe_2.917Co_0.083GaTe₂ hold a Curie temperature of 253 K and 269 K, which decreases to 163 K and 173 K in monolayer and bilayer Fe_2.67Co_0.33GaTe₂ systems, respectively. We find a giant anomalous Nernst conductivity (ANC) of 6.03 A/(K·m) in the monolayer Fe_2.917Co_0.083GaTe₂ at −30 meV, and this is further enhanced to 11.30 A/(K·m) in the bilayer Fe_2.917Co_0.083GaTe₂ at −20 meV. Moreover, the bilayer Fe_2.917Co_0.083GaTe₂ structure has a large anomalous thermal Hall conductivity (ATHC) of −0.14 W/(K·m) at 100 K. Overall, we find that the Fe_3−xCo_xGaTe₂ (x = 0.083, 0.167, 0.250, and 0.330) structures have better anomalous transverse transport performance than the pristine Fe₃GaTe₂ system and can be used for potential spintronics and spin caloritronics applications.