Effect of tension on coercive force in amorphous (Fe1−xCox)77Si10B13 ribbons

Coercive force Hc was measured from observation of hysteresis loop as a function of tension σo and x in amorphous (Fe1−xCox)77Si10B13 ribbons. Tensions up to 4×109 dyne/cm2 and ac field, 380 Hz and 2.5 Oe max., were applied along the axis of straight ribbon. In the positive λs alloys (x?0.9), hysteresis loop easily became square type with increasing σo: After square type was attained, Hc increased almost linearly with further increase of σo. The rate of this increase, ΔHc/Δσo, was found to vary with x and to be nearly proportional to λs(x)/Ms(x). This result was qualitatively well explained from the viewpoint of wall coercive force with assumption of simple domain configuration.