Phase evolution and field-induced magnetic anisotropy of the nanocomposite three-phase fcc, hcp, and amorphous soft magnetic alloy Co_(89)Zr_7B_4

摘要

Crystallization and field-induced magnetic anisotropy were investigated for a Co_(89)Zr_7B_4 alloy. A mixture of nanocrystalline fcc and hcp phases surrounded by an amorphous matrix is present after primary crystallization. For annealing in a 2 T transverse field, the observed anisotropy fields and field-induced anisotropies are H_K approx 12-15 Oe and K_U approx 550-680 J/m~3 for field annealed amorphous ribbons as compared to H_K approx 18-19 Oe and K_U approx 800-850 J/m~3 for field crystallized ribbons. In comparison with the corresponding Fe-based alloy, the relatively high Curie temperature and large field-induced anisotropy of the field annealed amorphous ribbons indicate that the intergranular amorphous phase may provide a relatively more significant contribution to the field-induced anisotropy of Co-based nanocomposite ribbons such as Co_(89)Zr_7B_4.