Stochastic oscillations of magnetic flux in the toroid sample of lead-doped lanthanum manganite

The dynamics of magnetic flux variations in a toroidal sample of the La0.6Pb0.4MnO3 manganite was investigated. Experiments were carried out when the ac magnetic field was applied perpendicular to the dc one. It is shown that under some conditions, several regimes of complex oscillations of magnetic flux can be excited. Evolution of these oscillations as a function of frequency of ac and magnitude of dc magnetic fields was investigated. The signs of existence of the stochastic regime of oscillations were found.