Abstract

The magnetism of a small cluster of magnetic atoms at finite temperatures is numerically investigated. The evolution of the system towards thermal equilibrium is studied, and the possibility of occurrence of vortexlike excitations in the arrangement of the magnetic moments within the cluster is pointed out. The magnetization curve as a function of temperature, of a small magnetic particle, suggests that magnetic clusters in granular metals are not saturated even at room temperature. The relevance of the present results to the understanding of the magnetic behavior of granular metals is discussed. ©1999 The American Physical Society.