Analytical and computational study of magnetization switching in kinetic Ising systems with demagnetizing fields

Howard L. Richards, M. A. Novotny, and Per Arne Rikvold
Phys. Rev. B 54, 4113 – Published 1 August 1996
PDFExport Citation

Abstract

An important aspect of real ferromagnetic particles is the demagnetizing field resulting from magnetostatic dipole-dipole interactions, which causes large particles to break up into equilibrium domains. Sufficiently small particles, however, remain single domain in equilibrium. This makes them particularly promising as materials for high-density magnetic recording media. In this paper we use analytic arguments and Monte Carlo simulations to quantitatively study the effects of the demagnetizing field on the dynamics of magnetization switching in two-dimensional, single-domain, kinetic Ising systems. For systems in the weak-field ‘‘stochastic region,’’ where magnetization switching is on average effected by the nucleation and growth of a single droplet, the simulation results can be explained by a simple model in which the free energy is a function only of magnetization. In the intermediate-field ‘‘multidroplet region,’’ a generalization of Avrami’s law involving a magnetization-dependent effective magnetic field gives good agreement with the simulations. The effects of the demagnetizing field do not qualitatively change the droplet-theoretical picture of magnetization switching in highly anisotropic, single-domain ferromagnetic grains, which we recently proposed [J. Magn. Magn. Mater. 150, 37 (1995)]. © 1996 The American Physical Society.

  • Received 6 December 1995

DOI:https://doi.org/10.1103/PhysRevB.54.4113

©1996 American Physical Society

Authors & Affiliations

Howard L. Richards

  • Center for Materials Research and Technology, Department of Physics, and Supercomputer Computations Research Institute, Florida State University, Tallahassee, Florida 32306-3016
  • Department of Solid State Physics, Riso/ National Laboratory, DK-4000 Roskilde, Denmark

M. A. Novotny

  • Supercomputer Computations Research Institute, Florida State University, Tallahassee, Florida 32306-4052
  • Department of Electrical Engineering, 2525 Pottsdamer Street, Florida A&M University–Florida State University, Tallahassee, Florida 32310-6046

Per Arne Rikvold

  • Center for Materials Research and Technology, Department of Physics, and Supercomputer Computations Research Institute, Florida State University, Tallahassee, Florida 32306-3016;
  • Centre for the Physics of Materials and Department of Physics, McGill University, Montréal, Québec, Canada;
  • Department of Fundamental Sciences, Faculty of Integrated Human Studies, Kyoto University, Kyoto, Japan

References (Subscription Required)

Click to Expand
Issue

Vol. 54, Iss. 6 — 1 August 1996

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×