Barkhausen noise in 5% Mo-78.5% Ni permalloy with rolling texture

Abstract

Measurements of the Barkhausen noise have been made on 50% cold-rolled polycrystalline permalloy specimens cut at various angles to the rolling direction, at magnetising frequencies ranging from 0.01 to 0.5 Hz. The peak of the amplitude distribution shifted from 45 to 42.5 dB and the total number of Barkhausen pulses decreased as the specimen angle increased from 10 degrees to 70 degrees . The power of the frequency spectrum of the Barkhausen noise decreased markedly and the slope of the spectrum decreased from f-4 to f-2 due to the reduction of clustering as the specimen angle increased. As the magnetising frequency increased from 0.01 to 0.5 Hz, the peak of the amplitude distribution shifted towards a high amplitude from 45 to 46.5 dB, the total number of Barkhausen pulses decreased and the power of the frequency spectrum increased due to overlapping of the Barkhausen pulses.