Preparation of soft magnetic FeCo-based films for writers.

New soft magnetic head materials, the nanocrystalline FeCoAlOC thin films, were prepared by introducing C element in epoxy resin during rf sputtering of FeCoAlO films. When Al2O3 was cosputtered with FeCo, soft magnetic properties of thin films were highly improved: the coercive force decreases from dozen of oersted to several oersted (Hch∼4.8 Oe and Hce∼6.5 Oe). With further addition of carbon, the thin films exhibit excellent soft magnetic properties and good high frequency response: the coercivity is as low as 1.0 Oe, with saturation Bs>20 kG, permeability μ′>500 when f≤1.0 GHz, and cutoff frequency around 1.7 GHz. The measurement of microstructure shows that the good magnetic properties are correlated with the small gain size of film. [ABSTRACT FROM AUTHOR]