Power Spectrum of the Barkhausen Noise of Various Magnetic Materials

Abstract

This work describes a simple apparatus used to measure power spectra of Barkhausen noise in an analysis frequency band between 25 and 10⁴ cps. Because previous work by the authors showed that when the specimen is in the form of a closed magnetic circuit and unlaminated the intensity of the noise has but small dependence on the core dimensions, unlaminated ring‐shaped samples were used in this work. Spectra obtained with a magnetizing field frequency of 0.1 cps are given for iron, 6% silicon iron, grain‐oriented silicon iron, ultraperm, mumental, nickel, and Permalloy C. It is observed that the intensity of the noise depends to a large extent on the nature of the ferromagnetic material. No interpretation of this fact is given, as it appears very complicated to understand.