Temperature-driven spin reorientation transition in Fe/Mo(110) nanostructures

Using low-temperature spin polarized scanning tunneling microscopy and spectroscopy, we observed a temperature-driven spin-reorientation transition (SRT) in Fe double layer (DL) nanostructures grown by step-flow growth on Mo(110). Magnetization components along the vertical and horizontal directions were detected with 4/16 ML Co/10 ML Au/W(110) tips with out-of-plane (4 ML Co) and in-plane (16 ML Co) magnetic sensitivities. The magnetic easy axis of the Fe DL nanostructures continuously rotates from the vertical direction at 5 K to an in-plane direction at 20 K. The rotation angle is independent of the size of the Fe DL nanostructures. Both out-of-plane and in-plane magnetic asymmetries show a strong decrease at the SRT.