Influence of local anisotropy fluctuation on soft magnetic properties of the sputtered Fe-Si-Al alloy films

Effective permeability, mu /sub eff/, uniaxial anisotropy field, H/sub k/, and local anisotropy fluctuation represented as magnetic ripple, SA/sup -5/8/ (S is the structure constant and A/sup -5/8/ is a coefficient equal to the power of the exchanges stiffness constant), were systematically studied as a function of composition and film thickness for Fe-Si-Al ternary alloy films. The influence of H/sub k/ and SA/sup -5/8/ on mu /sub eff/ is discussed in connection with the film structure. The magnitude of mu /sub eff/ was found to depend strongly on the magnitude of microscopic local anisotropy fluctuation. A decrease of the film thickness caused a marked increment in SA/sup -5/8/ due to the change of the preferred grain orientation from