Switching field fluctuations in a glass-coated Fe-rich amorphous microwire

Abstract Spontaneous experimental spread, Δ H s , of the switching field, H s , (switching field fluctuations) during the re-entrant magnetization process of Fe-rich (Fe 65 Si 15 B 15 C 5 ) microwire (metallic nucleus diameter of around 10 μm) exhibiting rectangular hysteresis loop has been observed at room temperature. Shape of the switching field distribution has been measured and analyzed in terms of a thermoactivational mechanism. The model predicts the lineal dependence of the logarithm of Barkhausen jump probability, d w , on reduced switching field fluctuation, Δ h =Δ H s / H sm . Observed d w (Δ h ) dependence fits satisfactorily to the predicted semi-logarithmic dependence.