Aging in a two-dimensional Ising model with dipolar Interactions

JULIO H. TOLOZA; FRANCISCO A. TAMARIT; SERGIO A. CANNAS

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

The American Physical Society

Lugar: College Park, Maryland; Año: 1998 vol. 58 p. 8885 - 8888

0163-1829

Aging in a two-dimensional Ising spin model with both ferromagnetic exchange and antiferromagnetic dipolar interactions is established and investigated via Monte Carlo simulations. The behaviour of the autocorrelation function $C(t,t_w)$ is analyzed for different values of the temperature, the waiting time $t_w$ and the quotient $delta=J_0/J_d$, $J_0$ and $J_d$ being the strength of exchange and dipolar interactions respectively. Different behaviours are encountered for $C(t,t_w)$ at low temperatures as $delta$ is varied. Our results show that, depending on the value of $delta$, the dynamics of this {f non-disordered} model is consistent either with a slow domain dynamics characteristic of ferromagnets or with an activated scenario, like that proposed for spin glasses.