Ultrahigh-frequency ferromagnetic properties of FeCoHf films deposited by gradient sputtering

Nanocrystalline FeCoHf films with Hf composition gradient were prepared by gradient sputtering method at room temperature. A uniaxial magnetic anisotropy with high anisotropy field H-k up to 547 Oe was achieved after magnetic annealing with external field along the gradient direction. Ultrahigh ferromagnetic resonance frequency over 7 GHz was obtained in magnetic annealed gradient sputtered films. The origin of ultrahigh ferromagnetic properties in gradient sputtered films is discussed. (C) 2008 American Institute of Physics.