Growth, strain, and spin-orbit torques in epitaxial Ni-Mn-Sb films sputtered on GaAs

We report current-induced spin torques in epitaxial NiMnSb films on a commercially available epiready GaAs substrate. The NiMnSb was grown by cosputtering from three targets using optimized parameters. The films were processed into microscale bars to perform current-induced spin-torque measurements. Magnetic dynamics were excited by microwave currents, and electric voltages along the bars were measured to analyze the symmetry of the current-induced torques. We found that the extracted symmetry of the spin torques matches those expected from spin-orbit interaction in a tetragonally distorted half-Heusler crystal. Both fieldlike and dampinglike torques are observed in all the samples characterized, and the efficiency of the current-induced torques is comparable to that of ferromagnetic metal/heavy-metal bilayers.

Automated summary

Current-induced spin torques were studied in epitaxial NiMnSb films on a commercially available epiready GaAs substrate, showing a symmetry that matches those expected from spin-orbit interaction in a tetragonally distorted half-Heusler crystal. Both fieldlike and dampinglike torques were observed in all samples tested, and the efficiency of the current-induced torques was comparable to that of ferromagnetic metal/heavy-metal bilayers.