Ferromagnetic resonance investigation of nanocrystalline gadolinium

An elaborate lineshape analysis of the ferromagnetic resonance (FMR) spectra taken in the temperature range 113K to 323K on nanocrystalline gadolinium shows that the complex temperature variation of the anisotropy field in bulk single crystal Gd still plays a decisive role in determining the magnetic properties of Gd in nanocrystalline form. The unusually broad FMR linewidth arises from nearly random variation of the easy direction of magnetization from grain to grain as well as from the magnetic inhomogeneities at the grain boundaries. The scaling equation of state analysis reveals a reduced value of the Curie temperature compared to that of the bulk. (author)