Co/Pt multilayer dot switching experiments with sub-nanosecond pulse field

Magnetization switching experiments on a single Co/Pt multilayer dot of 300 nm in diameter have been carried out using pulse fields with the duration τ_p 0.6-10.3 ns and the amplitude up to 3.2 kOe perpendicular to the film plane. The switching field increases from 3.4 kOe in a quasistatic field to 4.56 kOe in a pulse field for τ_p 0.6 ns. From the analysis of the field duration dependence of the switching field based on the Néel-Arrhenius model, the energy barrier E₀ 214 k_BT and the intrinsic switching field H₀ 5.0 kOe were obtained. Those two parameters well reproduce the experimentally observed dependence of switching probability on pulse field amplitude, indicating that the magnetization behavior of the dot can be described by the thermal fluctuation effect for a single barrier over the field duration ranging from subnanoseconds to quasistatic regime.