2002/08/06 by Paolo Politi, Maria Gloria Pini, M. G. Pini
Physics and Astronomy · #Magnetic properties of thin films #Physics of Superconductivity and Magnetism #Theoretical and Computational Physics #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.66.214414
published as Phys. Rev. B 66, 214414 (2002) · 11 pages, 5 figures
arxiv created 2002/08/06 · openalex publication_date 2002/12/19 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We determine the effective dipolar interaction between single domain two-dimensional ferromagnetic particles (islands or dots), taking into account their finite size. The first correction term decays as 1/D5, where D is the distance between particles. If the particles are arranged in a regular two-dimensional array and are magnetized in plane, we show that the correction term reinforces the antiferromagnetic character of the ground state in a square lattice, and the ferromagnetic one in a triangular lattice. We also determine the dipolar spin-wave spectrum and evaluate how the Curie temperature of an ensemble of magnetic particles scales with the parameters defining the particle array: height and size of each particle and interparticle distance. Our results show that dipolar coupling between particles might induce ferromagnetic long range order at experimentally relevant temperatures. However, depending on the size of the particles, such a collective phenomenon may be disguised by superparamagnetism.