Dependence of barkhausen noise and second harmonics on magnetizing field orientation in 3% silicon iron

Abstract

The profile of Barkhausen noise (BN) and second harmonics are measured during B-H hysteresis loops as a function of the angle, Φ, between the H-field applied and the [001] axis in (110) [001] grain oriented 3% silicon iron. The BN profile for Φ = 0° splits into two peaks at the coercive force during a half cycle. The correspondence of BN peaks to those of second harmonics for Φ = 0° signifies the distribution of nucleation and annihilation of 180° domains at the negative and positive knees of the B-H loop, respectively. As Φ increases, for Φ ≥ 30° three new peaks appear on the BN profile in addition to the original two peaks associated with the nucleation and annihilation of 180° and zig-zag domains. However, the three new peaks, two outside and one between the original peaks, are not found as corresponding peaks in the second harmonics. The hysteresis loss increases with Φ due to the increased number of irreversible events during magnetization, while the marked decrease in BN energy at Φ = 30° is attributed to the small pulse height of non-180° walls involved in the zig-zag domain dynamics.