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

We present here a sketch of some numerical results offered by a micromagnet ism code based on the resolution of the Landau-Lifchitz equation. We have c omputed equilibrium configurations and dynamic susceptibilities to a weak f ield for magnetic materials with non-uniform magnetization and finite size and shape: cubic particles, finite-sized films with stripe domains and plat elets with in-plane magnetocrystalline anisotropy. The obtained results hav e been compared with analytical models and experimental results. Some non-t rivial 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.