Effects of boron contents on magnetic properties of Fe-Co-B thin films

Effects of B on the magnetic properties and high frequency characteristics of the Fe/sub 7/Co/sub 3/ based thin films were investigated through the microstructural analysis. It was found that B addition was very effective in increasing anisotropy field and resistivity and in decreasing coercivity without much loss of saturation magnetization. These enhancements were shown to be strongly related to grain size, grain morphology and preferred orientations. As a result, a Fe/sub 55/Co/sub 28/B/sub 17/ film with small dispersion angle of /spl sim/0.5/spl deg/ showed the ferromagnetic resonance frequency of 3.3 GHz and a linear effective permeability of /spl sim/350 up to 2 GHz.