Phase evolution and field-induced magnetic anisotropy of the nanocomposite three-phase fcc, hcp, and amorphous soft magnetic alloy Co89Zr7B4

Crystallization and field-induced magnetic anisotropy were investigated for a Co89Zr7B4 alloy. A mixture of nanocrystalline fcc and hcp phases surrounded by an amorphous matrix is present after primary crystallization. For annealing in a 2T transverse field, the observed anisotropy fields and field-induced anisotropies are HK∼12–15Oe and KU∼550–680J∕m3 for field annealed amorphous ribbons as compared to HK∼18–19Oe and KU∼800–850J∕m3 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 Co89Zr7B4.