Abstract
Magnetic properties of Co-Ni-Mo-Zr amorphous alloys prepared from the melt by rapid quenching were investigated. Ring samples (φ10-φ6) were stamped out from the ribbons and treated by the conventional annealing (CA) and/or rotating-magnetic-field annealing (RFA).
The soft magnetic properties of Co79Ni4Mo8Zr9 amorphous alloys, whose Tx was higher than Tc by 65 K, were improved slightly by the single process of these techniques. However, the two step annealing method (CA+RFA) improved the soft magnetic properties of this alloy remarkably. The relative permeability of this alloy depended on the external magnetic-field at the 2nd stage of the two-step annealing method. The highest relative permeability at 1 kHz was obtained by the sample annealed in the maximum field of 1.2 MA/m. This result is attributed to the large induced anisotropy of Co-Zr base alloys compared with the metal-metalloid base alloys.
