ON THE ORIGIN OF THE NONLINEAR AND CHAOTIC BEHAVIOR OF THE MAGNETOELASTIC RESONANCE

The nonlinear shape of the hysteresis loop M(H) and the dependence of the elastic constants on the magnetic state of the sample (Delta E eff ect) are shown to be two important sources of nonlinear effects that a ppear in magnetoelastic resonance experiments. The magnitude of these effects increases with the amplitude of the driving field and also is greatly dependent on the magnetic state at which the sample is biased, being more intense in the proximity of the anisotropy field (or satur ation field) where both M(H) and E(H) curves change steeply. The influ ence of both factors is further studied by solving numerically a diffe rential equation that accounts for the frequency response of the magne toelastic resonance. We force the solution to follow simplified models for M(H) and E(H), obtaining frequency dependencies in good agreement with the experimental results. (C) 1997 American Institute of Physics .