Strong harmonic generation in the chaotic regime of magnetization reversal in lanthanum manganite

A strong generation of harmonics at radio-frequencies was observed in a four-pole network with a toroidal core made of the manganite La0.6Pb0.4MnO3. Experiments were carried out with an ac radio-frequency electromagnetic field applied perpendicular to a dc magnetic field. It is shown that the threshold of generation of harmonics depends both on the frequency and on the magnitude of the ac and dc magnetic fields. Generation of harmonics takes place when the chaotic regime of the oscillations of magnetic flux is realized.