Micromagnetic study of a single-domain grain dynamics in magnetic recording media

This work reports a micromagnetic study of relaxation and switching of a single-domain-grain magnetization in the effective magnetic field of recording media. Based on the modified Landau-Lifshitz equation of micromagnetic dynamics, we have computed the relaxation time as a function of material-dependent constants of the magnetization precession damping, which is attributed in our model to the coupling between magnetization-vector and stress-tensor of magnetic anisotropy of recording media. We found that the recording media characterized by parameters, revealed in presented simulations, can respond to ac microwave field by ultrafast relaxation and switching in picoseconds regime.