Slow dynamics in a two-dimensional Ising model with competing interactions

The far-from-equilibrium low-temperature dynamics of ultrathin magnetic films is analyzed by using Monte Carlo numerical simulations on a two-dimensional Ising model with competing exchange (J0) and dipolar (Jd) interactions. In particular, we focus our attention on the low-temperature region of the (δ, T) phase diagram (where δ=J0/Jd) for the range of values of δ where striped phases with widths h=1 (h1) and h=2 (h2) are present. The presence of metastable states of the phase h2 in the region where the phase h1 is the thermodynamically stable one and vice versa was established recently. In this work we show that the presence of these metastable states appears as a blocking mechanism that slows the dynamics of magnetic domain growth when the system is quenched from a high-temperature state to a low-temperature state in the region of metastability. © 2003 The American Physical Society.