Spin canting of Ni/CoO/Fe films grown on curved MgO(001) substrate

Using element-resolved x-ray magnetic circular dichroism (XMCD) and x-ray magnetic linear dichroism (XMLD) measurements, we determined the spin orientations of Ni, CoO and Fe films in Ni/CoO/Fe films grown on a curved MgO(001) substrate. We find that the vicinal surface of MgO(001) substrate results in a spin canting towards out-of-plane direction in the Ni and CoO films as a result of the interfacial coupling. The Ni spin canting angle increases monotonically with the vicinal angle in the studied range of 0-17 degrees and the CoO spin canting angle increases more rapidly towards saturation only at a few degrees of the vicinal angle. The uniaxial magnetic anisotropy induced in the Ni layer by the Ni/CoO interfacial coupling is quantitatively determined and is shown to increase monotonically with the vicinal angle. Our result provides a new pathway for tailoring the spin orientation by modifying the substrate surface symmetry in combining with the ferromagnetic/antiferromagnetic interfacial interaction in thin-film based spintronic devices.

Automated summary

Using XMCD and XMLD measurements, this study determined the spin orientations of Ni, CoO and Fe films in Ni/CoO/Fe films grown on a curved MgO(001) substrate. The results showed that the vicinal surface of the substrate caused a spin canting towards the out-of-plane direction in the Ni and CoO films due to interfacial coupling. The spin canting angle increased with the vicinal angle and this relationship was quantitatively determined. This research provides a new pathway for tailoring spin orientation in thin-film based spintronic devices by modifying the substrate surface symmetry in combination with ferromagnetic/antiferromagnetic interfacial interaction.