Atomistic Modeling of the Interlayer Coupling Behavior in Perpendicularly Magnetized $L1_{0}$-FePt/Ag/ $L1_{0}$-FePt Pseudo Spin Valves

An atomistic model based on a classical spin Hamiltonian and a Landau-Lifshitz-Gilbert (LLG) equation was utilized to simulate and gain understanding of the magnetic, interfacial, and reversal properties of perpendicular anisotropy
L
1
₀
-FePt/Ag/
L
1
₀
-FePt pseudo spin valves, with different interfacial roughness, representing the experimentally observed behavior of the interface where the Ag spacer layer was postannealed at different temperatures. Simulation results showed that the influence of the Ag spacer on the independent switching of the FePt layers became stronger with a greater degree of interlayer mixing under higher temperature treatment. This was the result of an increased magnetic polarization of Ag with a decrease in Ag spacer thickness. Furthermore, with greater intermixing the magnetization reversal of the harder fixed FePt layer also changed from a coherent reversal process to one which took place via nucleation and propagation of reversed domains.