INFLUENCE OF DC BIAS FIELD, EXCITATION AND DETECTION FREQUENCIES ON MAGNETIC BARKHAUSEN NOISE-ANALYSIS

The micromagnetic Barkhausen emissions, widely known as Barkhausen noi se, are quite dependent on excitation and detection frequencies. The i nput variables to generate these emissions are amplitude, wave form an d frequency of magnetic excitation field. When a DC bias fieId is coup led with an AC magnetic field, this compIex excitation give rises to d istortion of the magnetic hysteresis loop. Recent work showed the freq uency dependence of hysteresis curves in ferromagmetic materials. Sinc e there is a strong correlation between the location on the BII loop a nd Barkhausen, comprehending the magnetization mechanisms at each loca tion is essential. The current investigation indicated significant cha nges in voltage wave forms, pulse height spectra, frequency spectra an d RMS voltages of magnetic Barkhausen noise in magnetic materials with different DC bias fields, detection and excitation frequencies.