  Magnetization reversal in magnetic nanostructures is investigated numerically
over time-scales ranging from fast switching processes on a picosecond scale to
thermally activated reversal on a microsecond time-scale. A simulation of the
stochastic Landau-Lifshitz equation of motion is used as well as a time
quantified Monte Carlo method for the simulation of classical spin systems
modeling magnetic Co nanoparticles. For field pulses larger than the
Stoner-Wohlfarth limit spin precession effects govern the reversal behavior of
the particle while for lower fields a magnetization reversal is only possible
when it is assisted by thermal fluctuations.
