Deposition order dependent magnetization reversal in pressure graded Co/Pd films

Abstract

Time and temperature dependences of the magnetization reversal in a Co ∕ Pd multilayer film

Realization of ground-state artificial skyrmion lattices at room temperature

“…Lastly, Co was sputtered over the irradiated anti-dot arrays, forming edge-cut Co dots after a lift-off process. The Co/Pd films exhibit (111) texture and the Co dots are polycrystalline, respectively, as reported in previous studies 33 . The skyrmion texture was then prepared by a designed field sequence, as detailed in Methods: the Co/Pd underlayer was first saturated in the positive perpendicular direction; then the perpendicular field was removed and a much smaller in-plane field was applied to saturate the Co dots parallel to their flat edge; lastly, a negative perpendicular field was applied as the in-plane field was removed to set the polarity, and finally the perpendicular field was removed.…”

Realization of Ground-State Artificial Skyrmion Lattices at Room Temperature

“…Lastly, Co was sputtered over the irradiated anti-dot arrays, forming edge-cut Co dots after a liftoff process. The Co/Pd films exhibit (111) texture and the Co dots are polycrystalline, respectively, as reported in previous studies 33 . The skyrmion texture was then prepared by a designed field sequence, as detailed in Methods: the Co/Pd underlayer was first saturated in the positive perpendicular direction; then the perpendicular field was removed and a much smaller in-plane field was applied to saturate the Co dots parallel to their flat edge; lastly, a negative perpendicular field was applied as the in-plane field was removed to set the polarity, and finally the perpendicular field was removed.…”

Magnetization reversal in perpendicularly magnetized L1 FePd/FePt heterostructures

“…The roughness-induced pinning prevents unhindered expansion of labyrinth domains. 28,31 The reversal process in the thicker bilayers is thus dominated by nucleation, as demonstrated by the steady increase of the reversed bubble domains shown in Figs. 3(d)-3(i)), and the collapsed FORC feature a 1 in the thicker film (Fig.…”

“…This is consistent with the effects of graded magnetic anisotropy along the film depth and higher disorders, as seen in Co/Pd and Co/Pt systems. 27,28,31 The significant change of the magnetization reversal mode by adding an FePd film on top of an FePt layer can be attributed to the interplay between weak perpendicular anisotropy, structural inhomogeneities and demagnetization energy. In pure FePt films (Figs.…”

“…4(d)) that are similar to those for the Co/Pt and Co/Pd multilayers. 18,[30][31][32] In summary, we have prepared epitaxial L1 0 FePd/FePt (24 nm) heterostructures on MgO(001) substrates and studied the evolution of the magnetization reversal mechanism with the FePd layer thickness by FORC and Kerr microscopy. For thin FePd samples, magnetic moments in both layers are strongly coupled together and remain perpendicular to the films; the magnetization reversal process is initialized by nucleation of reversed domains and mainly accomplished by irreversible domain wall motion.…”