1996/11/07 by Howard L. Richards, M. Kolesík, M. Kolesik +4 · 52 citations
Materials Science · Mathematics · Physics and Astronomy · #Block Copolymer Self-Assembly #Boundary (topology) #Classical mechanics #Condensed matter physics #Ferromagnetism #Ising model #Kinetic energy #Magnetic field #Magnetic properties of thin films #Magnetization #Materials science #Mathematical analysis #Mathematics #Nanoscopic scale #Nanotechnology #Physics #Quantum mechanics #Theoretical and Computational Physics #cond-mat
paper · pdf · doi:10.1103/physrevb.55.11521
published in Physical review. B, Condensed matter 55(17), 11521-11540 (American Physical Society) · RevTex, 48 pages, 13 figures
arxiv created 1996/11/07 · openalex publication_date 1997/05/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Magnetization switching in highly anisotropic single-domain ferromagnets has been previously shown to be qualitatively described by the droplet theory of metastable decay and simulations of two-dimensional kinetic Ising systems with periodic boundary conditions. In this paper we consider the effects of boundary conditions on the switching phenomena. A rich range of behaviors is predicted by droplet theory: the specific mechanism by which switching occurs depends on the structure of the boundary, the particle size, the temperature, and the strength of the applied field. The theory predicts the existence of a peak in the switching field as a function of system size in both systems with periodic boundary conditions and in systems with boundaries. The size of the peak is strongly dependent on the boundary effects. It is generally reduced by open boundary conditions, and in some cases it disappears if the boundaries are too favorable towards nucleation. However, we also demonstrate conditions under which the peak remains discernible. This peak arises as a purely dynamic effect and is not related to the possible existence of multiple domains. We illustrate the predictions of droplet theory by Monte Carlo simulations of two-dimensional Ising systems with various system shapes and boundary conditions.