Spin Hall Conductivity of W100-xSix Alloys in A15 Structure: A Comprehensive Study

Spin Hall conductivity (SHC) of WSUB100-x/SUBSiSUBx/SUB alloys in the A15 structure is investigated using first-principles calculations. Various concentrations of x (0, 3.125, 6.25, 12.5, and 25 %) are calculated for different configurations. Formation energy is used to investigate structural stability, where the substitution Si into bcc sites is energetically favorable. For each x, the thermodynamic average of SHC (σSUBxy/SUB) is taken. Notably, at x = 3.125 %, σSUBxy/SUB= -1306 S/cm is the largest among WSUB100-x/SUBSiSUBx/SUB alloys, which is enhanced by 59 % over β-W of σxy = -818 S/cm. The enhanced SHC is explained by negative Berry curvature.