Fig. 6: Magnetization dynamics of gadolinium in amorphous Fe74Gd26.

Experimental and Simulated demagnetization dynamics by TR-XMCD and atomistic spin dynamics of Gd in Fe74Gd26 for 40 mJ/cm2 incident and 1.2 mJ/cm2 absorbed fluences. The last fluence has been adjusted to fit our experimental data. The blue (red) symbols and lines are the results for the P (AP) configurations. Solid lines in red (blue) are the simulations for the antiparallel (parallel) STT and the associated positive (negative) spin currents. In simulations the STT spin current polarization (SHE) is defined as “positive” for the antiparallel orientation to the Fe 3d magnetization of the Fe sub-lattice (MFe).