Temperature dependence of the magnetization of glassy and nanocrystalline Fe/sub 82/M/sub 7/B/sub 10/Cu/sub 1/ [M=Zr,Hf,Nb] alloys with high permeability at high frequencies

We report the salient features of the magnetic properties of glassy and nanocrystalline Fe/sub 82/M/sub 7/B/sub 10/Cu/sub 1/ [M=Zr,Hf,Nb] alloys. By controlled annealing, fine 4-6 nm grain size bcc-Fe is formed in a ductile glassy matrix, which gives good soft magnetic properties like permeability and low coercive field. From the low temperature magnetic data and ferromagnetic resonance studies we determine and compare the changes in the spin wave exchange stiffness constants as well as the range of exchange interactions in the glassy and nanocrystalline states.