  We report the first experimental observation of noise-free stochastic
resonance by utilizing the intrinsic chaotic dynamics of the system. To this
end we have investigated the effect of an external periodic modulation on
intermittent signals observed by high power ferromagnetic resonance in yttrium
iron garnet spheres. Both the signal-to-noise ratio and the residence time
distributions show the characteristic features of stochastic resonance. The
phenomena can be explained by means of a one-dimensional intermittent map. We
present analytical results as well as computer simulations.
