Dr. Leo Ma (Culham Centre for Fusion Energy, UK)

Fundamentals and Applications of Magnetic Spin-Lattice Dynamics
When Nov 14, 2016
from 02:00 PM to 03:00 PM
Where LR8
Contact Name
Contact Phone 01865-283446
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Magnetic materials, such as iron, iron alloys and steels, are structural materials for nuclear fission and fusion applications, but the range of applications of these materials extends well beyond fission or fusion. Excitation of magnetic degrees of freedom in magnetics alloys contributes to the free energy and entropy, and influences the stability of crystal structures, defects configurations, defect production, migration rates, and various other properties. We developed spin-lattice dynamics simulation algorithms [1,2] that generalise molecular dynamics to the case of magnetic materials, and can simulate dynamic evolution involving non-collinear fluctuations of magnetic moments and translational motion of atoms on a million atom scale. Recently, we have released a spin-lattice dynamics code SPILADY [3], implemented for both CPU and GPU computers.

Spin-lattice dynamics simulations have been applied to a diverse range of applications in fission and fusion, and beyond. For example, simulations explain the anomalous variation of elastic constants, lattice structure, vacancy formation and migration energy near the Curie temperature. Other applications explored using spin-lattice dynamics simulations include the correlated dynamics of magnetic moments in thin films, ultrafast demagnetization of materials by a laser pulse, and ultra-high frequency magnetic refrigeration.

[1] Pui-Wai Ma, C. H. Woo, and S. L. Dudarev, Phys. Rev. B 78, 024434 (2008)

[2] Pui-Wai Ma, S. L. Dudarev, and C. H. Woo, Phys. Rev. B, 85, 184301 (2012)

 [3] Pui-Wai Ma, S. L. Dudarev and C. H. Woo, Comp. Phys. Comm., 207, 350 (2016); http://spilady.ccfe.ac.uk

This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053 and from the RCUK Energy Programme [grant number EP/I501045]. The views and opinions expressed herein do not necessarily reflect those of the European Commission.