Numerical simulations of isolated particles susceptibilities: effects of shape and size

We present here a sketch of some numerical results offered by a micromagnetism code based on the resolution of the Landau-Lifchitz equation. We have computed equilibrium configurations and dynamic susceptibilities to a weak field for magnetic materials with non-uniform magnetization and finite size and shape: cubic particles, finite-sized films with stripe domains and platelets with in-plane magnetocrystalline anisotropy. The obtained results have been compared with analytical models and experimental results. Some non-trivial effects have been pointed out (like surface modes) and fine details can be disclosed by susceptibility maps. (C) 2001 Elsevier Science B.V. All rights reserved.