Tunable magnetization damping in transition metal ternary alloys

We show that magnetization damping in Permalloy, Ni80Fe20, can be enhanced sufficiently to reduce postswitching magnetization precession to an acceptable level by alloying with the transition metal Os (osmium). The damping increases monotonically upon raising the Os concentration in Permalloy, at least up to 9% of Os. Other effects of alloying with Os are suppression of magnetization and enhancement of in-plane anisotropy. Magnetization damping also increases significantly upon alloying with the five other transition metals included in this study (4d elements: Nb, Ru, Rh; 5d elements: Ta, Pt) but never as strongly as with Os.