engleski

Zero coercive field in twisted Fe80B20 amorphous ribbons carrying an alternating current

The effects of the direct (Jd) and alternating (J) core currents on the M-H loops of stress-free and twisted (through 360º over the length of 20 cm) Fe80B20 amorphous ribbons are investigated. Whereas J has little effect on the coercive field Hc of the stress-free Fe80B20 ribbons, Hc of the twisted ribbon decreases linearly with the amplitude J0 of J and reaches zero for J0 = 92 mA. Hc = 0 occurs when the projection of the self- field of J0 on the domain magnetization (I) reaches the magnitude which is sufficient to unpin the domain walls (DW) responsible for Hc at zero magnetizing field H. The effects of Jd on the M – H loops show that torsion affects the strengths of the DW pinning centres and the directions of I in Fe80B20 ribbon in a which facilitates the achievement of Hc = 0. A possibile application of Hc = 0 is mentioned.

amorphous materials ; magnetic properties

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