The effect of annealing on magnetic properties of Co/Gd multilayers

•We have studied the magnetization of Gd/Co multilayers before and after annealing.•Annealing leads to mixing of Co and Gd layers with alloy formation at the interface.•Domain wall propagation is dominated at the reversal process.•Coercivity increase is proportional to the number of interface in the multilayers.

The impact of annealing on the structural and magnetic properties of sputtered [Gd/Co]n multilayers has been researched. Structural and phase contrast of atomic force microscope measurements at the imaging of the facet sample cross-section demonstrate that thermal annealing process at 700 K leads to intermixing between Co and Gd layers, i.e. the alloy formation around the former interface. Magnetometry measurements are coherent with such CoGd alloying. Annealing reinforces the domination of domain wall propagation in the magnetization reversal mechanism. Low temperature magnetometry analysis seems to indicate that CoGd mixing due to annealing may occurs over 2 nm apart from initial Co/Gd interface.