The formation of hysteretic magnetic properties in amorphous alloys of various classes upon thermomagmetic treatment in a transverse magnetic field

Abstract

In this paper, we have studied the effects of the thermomagnetic treatment in a transverse magnetic field (TMaT_⊥) on the permeability of the amorphous alloy Co₆₉Fe_3.7Cr_3.8Si_12.5B₁₁ with such a low saturation magnetostriction (λ_s 10^–7) that, in the ribbons of this alloy rolled into a toroid, a sharp longitudinal magnetic texture is observed (K_sq > 0.90). It has been revealed that the permeability μ₄ (H = 4 mOe, f = 1 kHz) as a function of the annealing temperature or time of holding at a temperature is described by a curve with a maximum. This maximum is observed at a coefficient of the squareness of the hysteresis loop K_sq,m in the range of 0.2 ≤ K_sq,m ≤ 0.4. The regimes of the TMaT have been determined that provide optimum values of the permeability μ₄ (15000) without a loss of the ductile state of the ribbons of this alloy. Based on the example of an iron-based alloy of composition Fe₅₇Co₃₁Si_2.9B_9.1 with λ_s = 35 × 10^–6, it has been shown that the formation of the hysteretic magnetic properties upon the TMaT_⊥ depends substantially on the magnitude of the magnetostriction and the Curie temperature of the amorphous alloys.