Non-Linear Behavior of the Magnetoelastic Resonance in Fe-Rich Metallic Glasses

Fe-rich metallic glasses show complex and non-linear magnetoelastic resonance phenomena, giving rise to the so-called "magnetoelastic bifurcation" and even to chaotic behavior. In resonance-antiresonance experiments only the first harmonic of the response at the frequency of excitation is detected. Non-linearity gives rise to higher order harmonics in the response, whose magnitude increases with the amplitude of the excitation. In this work, we Present the evolution of the harmonic content of the resonant response in some Fe-rich metallic glasses. This evolution is studied as a function of the bias field and the amplitude and frequency of the excitation in samples both as quenched and after transverse field annealing conditions. Spatial and temporal contributions to the harmonics are obtained and compared in the moderate excitation range. Some effort is made to reproduce the results using computer simulations. In the highest range of values of the excitation field, half frequency components of all the harmonics and chaotic behavior appear.