Micromagnetic Exchange Energy Formulations
Michael Donahue
Mathematical and Computational Sciences Division
Tuesday, September 16, 2003 15:00-16:00,
Room 145, NIST North (820)
Gaithersburg
Tuesday, September 16, 2003 13:00-14:00,
Room 4511
Boulder
Abstract:
Micromagnetics is a continuum theory that models behavior of magnetic
materials at the nanometer scale. Typically, four component energies
are considered: Zeeman (applied magnetostatic), demagnetization
(self-magnetostatic), crystalline anisotropy, and exchange. The
exchange energy represents the adjacent spin-spin interaction that
gives rise to ferromagnetism. Defined in terms of the gradient of the
magnetization components, it is especially sensitive to
discretization details in a numerical implementation. This talk
examines several discretization methods for the exchange energy term,
and presents results on convergence rates, boundary conditions, and
iterative stability. Effects of the discretization method on vortex
mobility and Neel wall collapse are also presented.
Contact: A. J. KearsleyNote: Visitors from outside NIST must contact
Robin Bickel; (301) 975-3668;
at least 24 hours in advance.
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