Atxitia, U., Hinzke, D., Chubykalo-Fesenko, O. et al. (5 more authors) (2010) Multiscale modeling of magnetic materials: Temperature dependence of the exchange stiffness. Physical Review B. 134440. -. ISSN 2469-9969
Abstract
For finite-temperature micromagnetic simulations the knowledge of the temperature dependence of the exchange stiffness plays a central role. We use two approaches for the calculation of the thermodynamic exchange parameter from spin models: (i) based on the domain-wall energy and (ii) based on the spin-wave dispersion. The corresponding analytical and numerical approaches are introduced and compared. A general theory for the temperature dependence and scaling of the exchange stiffness is developed using the classical spectral density method. The low-temperature exchange stiffness A is found to scale with magnetization as m(1.66) for systems on a simple cubic lattice and as m(1.76) for an FePt Hamiltonian parametrized through ab initio calculations. The additional reduction in the scaling exponent, as compared to the mean-field theory (A similar to m(2)), comes from the nonlinear spin-wave effects.
Metadata
Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2009 American Physical Society. This is an author produced version of a paper published in PHYSICAL REVIEW B. Uploaded in accordance with the publisher's self archiving policy. |
Keywords: | GREEN FUNCTION THEORY, HEISENBERG-FERROMAGNET, SYSTEMS, NANOSTRUCTURES, EQUATION, FEPT |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Physics (York) |
Depositing User: | Repository Administrator York |
Date Deposited: | 18 Nov 2010 16:16 |
Last Modified: | 06 Jan 2024 00:12 |
Published Version: | https://doi.org/10.1103/PhysRevB.82.134440 |
Status: | Published |
Refereed: | Yes |
Identification Number: | https://doi.org/10.1103/PhysRevB.82.134440 |
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