Ferromagnetic Resonance

Ferromagnetic resonance looks at magnetic materials and can yield important information as to their properties. The measurements can be made using the same spectrometer that we use for EPR but the linewidths involved are usually much larger than EPR lines. Using FMR it is in principle possible to measure the anisotropy fields of samples, as well as their saturation magnetisation.

We have used high field FMR to study, among other things, metal films, microwave ferrites and hard disc media. The spectrum below shows a 1200 Angstrom thick iron film.

ironfilm2

 

Note that the field scale is in Tesla, rather than in Gauss as for the EPR spectra.