  Nitrogen-vacancy centers in diamond have recently been established as
effective sensors of the magnetization dynamics in vicinal ferromagnetic
materials. We demonstrate sub-100 nm placement accuracy of
nitrogen-vacancy-containing nanodiamonds and use these as local sensors that
probe optically detected ferromagnetic resonance in mesoscopically patterned
Permalloy islands. These measurements reveal variations in the ferromagnetic
resonance signal at different sites on these structures with distinct behavior
in the edge and the bulk of patterned features. These test measurements
establish an easily implemented approach for spatially targeted measurements of
spin dynamics in mesoscale ferromagnets. In principle, the methodology can also
be extended to local studies of nanoscale ferromagnets such as single magnetic
nanowires and nanoparticles.
