Magneto-acoustic emission in wide ribbons of Metglas 2605SC and in steel bars

Magneto-acoustic emission (MAE) from wide ribbons of an amorphous ferromagnetic glass (Metglas 2605SC) and from a steel have been studied. The anisotropy of the ribbon is highlighted by applying the magnetic field along the axis of the plate or in a direction perpendicular to it. Two independent experimental set-ups with piezoelectric and inductive detectors coupled to synchronous amplifiers have been employed to simultaneously determine resonances of acoustic waves produced by the alternating magnetic field in the range of tens of KHz and with a spectrum analyzer in the range of hundreds of KHz.. These magnetoelastic resonances in the steel are compared with the results obtained when it is excited with more intense magnetic fields at the frequency of the AC line voltage.