The authors directly measure the magnetic damping parameter α in thin-film CoFeB and Permalloy (Py) nanomagnets at room temperature using a recently developed ferromagnetic resonance technique where the precessional mode of an individual nanomagnet can be excited by microwave-frequency spin-transfer torque and detected by the giant magnetoresistance effect. The authors obtain αCoFeB =0.014±0.003 and αPy =0.010±0.002, values comparable to measurements for extended thin films, establishing that patterned nanomagnets can exhibit magnetic damping that is consistent with that of unpatterned bulk material.
Bibliographical noteFunding Information:
This research was supported in part by the NSF/NSEC program through the Cornell Center for Nanoscale Systems and by the Office of Naval Research. Additional support was provided by NSF through use of the Cornell Nanoscale Science and Technology Facility/NNIN and the facilities of the Cornell Center for Materials Research.