Structure and FMR Characteristics of (CoFeB + SiO 2 ) Magnetic Composite Films

It is found that (CoFeB + SiO 2 ) composite films have a narrow spread of film surface protrusions at low concentrations of the metal alloy ( x < 0.35), while a wider spread and smooth distribution of the protrusions are observed at the large concentration ( x > 0.53). It is shown that the concentration dependence of the ferromagnetic resonance linewidth has a maximum at x = 0.45, due to the percolation structure of the films.