Soft Magnetic Properties of Annealed Co-Based Amorphous Co66Fe4Ni1B15Si14 Alloy Ribbon

The amorphous Co-based alloy Co_(66)Fe₄Ni₁B_(15)Si₁₄ (Metglas^® 2714A) is a suitable magnetic core material for high frequency operation. Appreciable reduction of the coercive force can be achieved by proper heat treatment. In this study, samples annealed at wide temperature range were analyzed using differential scanning calorimetry, high frequency B-H loop tester, X-ray diffractometer and resistivity meter. The results show that coercive force at 10 ㎑ decreases with increasing annealing temperature up to 773 K, but dramatically increases above this temperature. The squareness shows that the magnetic anisotropy on longitudinal direction of the as-cast state remains up to 773 K. Above this temperature, it decreases down to 0.5 that represents random distribution of magnetic domains. The crystallization abruptly occurs between 781 K and 783 K.