FMR and Magnetic Properties of (CoFeB)m(SiO2)100-m Nanocomposite

Multilayer nanogranular film structures (CoFeB)m(SiO2)100-m have been investigated by ferromagnetic resonance (FMR). It is shown experimentally that for these films which magnetic phase content is below percolation threshold the variation of FMR fields is not related to the thickness of magnetic layers but can be explained by variation of the shape (elongation) of spheroidal magnetic granules. The observed results are explained within standard phenomenological FMR theory.