The Langevin-dynamics simulation of interacting fine magnetic particle systems

Using Langevin dynamics simulations, we have calculated the AC-suseeptibili ty chi = chi' + i chi " of disordered fine magnetic particle systems with t he dipolar interparticle interaction. We have shown that the shift of the c hi " (T)-peak with increasing particle concentration depends qualitatively on the single-particle anisotropy and quantitatively on the precession damp ing. (C) 2001 Elsevier Science B.V. All rights reserved.