Details

Autor(en) / Beteiligte

• Hinzke, D.
• Atxitia, U.
• Carva, K.
• Nieves, P.
• Chubykalo-Fesenko, O.
• Oppeneer, P. M.
• Nowak, U.

Titel

Multiscale modeling of ultrafast element-specific magnetization dynamics of ferromagnetic alloys

Ist Teil von

• Physical review. B, Condensed matter and materials physics, 2015-08, Vol.92 (5), Article 054412

Erscheinungsjahr

2015

Quelle

PROLA - Physical Review Online Archive

Beschreibungen/Notizen

• A hierarchical multiscale approach to model the magnetization dynamics of ferromagnetic random alloys is presented. First-principles calculations of the Heisenberg exchange integrals are linked to atomistic spin models based upon the stochastic Landau-Lifshitz-Gilbert (LLG) equation to calculate temperature-dependent parameters (e.g., effective exchange interactions, damping parameters). These parameters are subsequently used in the LandauLifshitzBloch (LLB) model for multisublattice magnets to calculate numerically and analytically the ultrafast demagnetization times. The developed multiscale method is applied here to FeNi (permalloy) as well as to copper-doped FeNi alloys. We find that after an ultrafast heat pulse the Ni sublattice demagnetizes faster than the Fe sublattice for the here-studied FeNi-based alloys.