English

Magnetic relaxation and dipole-coupling-induced magnetization in nanostructured thin films during growth: A cluster Monte Carlo study

Statistical Mechanics 2009-11-07 v2 Materials Science

Abstract

For growing inhomogeneous thin films with an island nanostructure similar as observed in experiment, we determine the nonequilibrium and equilibrium remanent magnetization. The single-island magnetic anisotropy, the dipole coupling, and the exchange interaction between magnetic islands are taken into account within a micromagnetic model. A cluster Monte Carlo method is developed which includes coherent magnetization changes of connected islands. This causes a fast relaxation towards equilibrium for irregularly connected systems. We analyse the transition from dipole coupled islands at low coverages to a strongly connected ferromagnetic film at high coverages during film growth. For coverages below the percolation threshold, the dipole interaction induces a collective magnetic order with ordering temperatures of 1 - 10 K for the assumed model parameters. Anisotropy causes blocking temperatures of 10 - 100 K and thus pronounced nonequilibrium effects. The dipole coupling leads to a somewhat slower magnetic relaxation.

Keywords

Cite

@article{arxiv.cond-mat/0211290,
  title  = {Magnetic relaxation and dipole-coupling-induced magnetization in nanostructured thin films during growth: A cluster Monte Carlo study},
  author = {R. Brinzanik and P. J. Jensen and K. H. Bennemann},
  journal= {arXiv preprint arXiv:cond-mat/0211290},
  year   = {2009}
}

Comments

13 pages, 6 figures, revised manuscript