Local Ferromagnetic Resonance of Mesoscopic Structures Using Deterministically Placed Nanodiamonds

Nitrogen-vacancy (NV) centers in diamond offer a powerful method of measuring local magnetization dynamics in ferromagnetic materials. To date, measurements of ferromagnetic resonance (FMR) using NV centers have relied on a stochastic distribution of NV centers or their rough placement on a micron scale. Here, we demonstrate sub-100 nm placement accuracy of NV-containing nanodiamonds using an atomic force microscope and use this capability to perform optically detected FMR measurements on mesoscopically-patterned permalloy structures. By probing FMR using nanodiamonds deterministically placed at different sites on individual nanoscale ferromagnetic structures, we detect localized differences in the FMR signal and compare these with results from micromagnetic simulations. The technique has potential application in the study of localized spin dynamics of individual magnetic nanostructures as well for probing the dynamics of individual domain walls.