Increasing stochastic resonance effect in single-domain particles by applying permanent magnetic field transverse to easy axes

Stochastic resonance phenomenon is considered both theoretically and experimentally for system of single-domain magnetic particles having easy-axis anisotropy with auxiliary permanent magnetic field applied perpendicular their easy axes. That field leads to a shift of stable directions of the magnetic moment in space and diminish the height of potential barrier separating two minima. Nonmonotonic temperature dependencies of signal-to-noise ratio and dynamic magnetic susceptibility for Fe, Co, Ni fine particle are obtained at different values of the permanent magnetic field. Experiment was made as a radiospectroscopic study of an ensemble of Fe uniaxial nanoparticles fabricated by electron beam lithography. Our results obtained experimentally are in quite good agreement with theory, especially at low temperatures.