Barkhausen noise controlled by electric current through core

Barkhausen noise, thought of as mainly due to sudden irreversible jumps in the moving domain wall, can be controlled significantly by passing suitable galvanic currents (Iz) through the magnetic core. For example, the maximum jump amplitude in the straight 2826 MB Fe40Ni38Mo4B18 amorphous ribbon in as‐quenched state, excited by a 260 A/m, 0.001 Hz longitudinal field, and subject to an axial tensile stress of 1.6×106 N/m2, may be suppressed approximately 75 precent by a core‐current of 3.4×106 A/m2 (2 A through 12mm×50μm section), the decrease in amplitude being roughly linear over the Iz range. Similar reductions in magnetic noise have been observed in other tape cores, especially amorphous. For higher excitation frequencies (45 Hz), the fluctuation noise superposed on the output voltage waveform may be eliminated by a lower curent Iz. The method of current‐in‐core is also applicable to samples subject to shear forces as twist. A simple model for the magnetization is presented as one to explain this proce...