On Thursday, March 16 2023, we have the pleasure to welcome in SPINTEC Julien Tranchida, Research Scientist at CEA Cadarache. He will give us a seminar at 14:00, entitled:

Coupled magnetic and molecular dynamics: Methodology and application to the simulation of magneto-elastic effects in iron

Place: SPINTEC Seminar, CEA Building 10.05 auditorium 445 (access needs authorization *)
skype link : https://webconf.cea.fr/ioan-lucian.prejbeanu/C89D5FFJ
if this link does not work see below (**)

Abstract : Our presentation will first introduce a classical methodology aiming at simulating magnetization dynamics and magneto-elastic phenomena in materials. The approach is based on a coupling between classical spin dynamics and molecular dynamics. We will describe this approach and its implementation in the LAMMPS code [1]. After reviewing some recent applications of this methodology [2,3], we will point at some of its limitations.

We will then detail a computational scheme enabling the development of magneto-elastic interatomic potentials entirely based on first-principles results (DFT calculations). This scheme can be transposed to any material, and used to circumvent some of the limitations cited in the first section.

An application to iron, and in particular to the simulation of magneto-elastic effects (related to the magnon – phonon coupling) will be discussed. We will describe how this framework allowed the computation of the temperature dependence of some thermo-mechanical properties (elastic constants, magnetic anisotropy, magnetostrictive coefficients) with an accuracy close to the one expected from ab initio calculations [4,5]. Finally, we will discuss some perspectives, such as the deployment of those methods to the simulation of magnetic oxides (with applications in spintronics, simulation of nuclear fuels, or transport mechanisms in corrosion layers).

[1] Tranchida, J., Plimpton, S. J., Thibaudeau, P., & Thompson, A. P. (2018). Massively parallel symplectic algorithm for coupled magnetic spin dynamics and molecular dynamics. Journal of Computational Physics, 372, 406-425.
[2] Chauleau, J. Y., Chirac, T., Fusil, S., Garcia, V., Akhtar, W., Tranchida, J., … & Viret, M. (2020). Electric and antiferromagnetic chiral textures at multiferroic domain walls. Nature materials, 19(4), 386-390.
[3] Dos Santos, G., Meyer, R., Aparicio, R., Tranchida, J., Bringa, E. M., & Urbassek, H. M. (2021). Spin-lattice dynamics of surface vs core magnetization in Fe nanoparticles. Applied Physics Letters, 119(1), 012404.
[4] Nikolov, S., Wood, M. A., Cangi, A., Maillet, J. B., Marinica, M. C., Thompson, A. P., & Tranchida, J. (2021). Data-driven magneto-elastic predictions with scalable classical spin-lattice dynamics. npj Computational Materials, 7(1), 153.
[5] Nieves, P., Tranchida, J., Arapan, S., & Legut, D. (2021). Spin-lattice model for cubic crystals. Physical Review B, 103(9), 094437.

(*) Persons who do not have a CEA pass must request an entry authorization sufficiently in advance, before March 07, 2023 at admin.spintec@cea.fr

(**) IF THE LINK DOES NOT WORK,
try with skype web App : https://webconf.cea.fr/ioan-lucian.prejbeanu/C89D5FFJ?sl=1