Irreversibility line in the ferromagnet Co70.4Fe4.6Si15B10 alloy

Abstract
We report magnetization measurements in the zero magnetostriction Co70.4Fe4.6Si15B10 amorphous alloy. The measurements were carried out from room temperature up to 430 °C and for applied magnetic fields up to 45 Oe. An irreversible behavior in the zero-field and field-cooled magnetization was observed. The irreversibility line was fitted to a de Almeida–Thouless line with a crossover critical exponent φ=4.66. The experimental results are analyzed in the framework of an extended random anisotropy model for amorphous ferromagnets.