Mössbauer Study of Magnetic Properties of $Fe_{80-x}Co_{x}Zr_7Si_{13}$ (x = 0-30~at.%) Boron-Free Amorphous Alloys

Amorphous $Fe_{80-x}Co_{x}Zr_7Si_{13}$ (x = 0-30 at.%) alloys in which boron was completely replaced by silicon as a glass forming element have been prepared by melt quenching. Partial substitution of iron by cobalt caused the increase of the hyperfine field and saturation magnetization. The specialized rf-Mössbauer measurements revealed that all amorphous alloys studied are magnetically very soft. The rf-sidebands effect, related to magnetostriction, increases with the increase of Co content. In $Fe_{50}Co_{30}Zr_7Si_{13}$ sample the rf field exposure induced partial crystallization of amorphous phase that was attributed to mechanical deformations related to high frequency magnetostrictive vibrations induced by the rf field. The measurements of the hysteresis loop revealed that coercivity increases for higher Co content.