Monte Carlo model of domain growth in ultrathin magnetic films with perpendicular anisotropy

A Monte Carlo simulation of the domain growth process in ultrathin magnetic films with strong perpendicular anisotropy is carried out to study the effect of local variations of the domain-wall coercivity on the rate of domain expansion. The algorithm used simulates domain growth as a thermo-activated or viscous process, depending on the value chosen for the applied field. The rate of thermo-activated domain expansion is found to increase gradually to a constant value, attained when the domain size is sufficiently large. The depinning transition is rather sharp and not as wide as the distribution width of domain-wall coercivities. It may therefore be difficult to derive accurate information on the coercivity distribution from the measurement of v(H) curves in materials such as Au/Co/Au films (tCo=8 إ).