Engineering Pt/Co/AlO _x heterostructures to enhance the Dzyaloshinskii–Moriya interaction

Abstract

The study of interfacial Dzyaloshinskii-Moria interaction (DMI) in perpendicularly magnetized structurally asymmetric heavy metal /ferromagnet multilayer systems is of high importance due to the formation of chiral magnetic textures in the presence of DMI. Here, we report the impact of cobalt oxidation at the Co/AlOx interface in Pt/Co/AlOx trilayer structures on the DMI by varying the post-growth annealing time, Al thickness and substrate. To quantify DMI we employed magneto-optical imaging of the asymmetric domain wall expansion, hysteresis loop shift, and spin-wave spectroscopy techniques. We further correlated the Co oxidation with low-temperature Hall effect measurements and X-ray photoelectron spectroscopy. Our results emphasize the importance of full characterization of the magnetic films that could be used for magnetic random access memory technologies when subjected to the semiconductor temperature processing conditions, as the magnetic interactions are critical for device performance and can be highly sensitive to oxidation and other effects.

Skyrmions Subtractor Based on Dzyaloshinskii–Moriya Interaction Gate

“…However, the control of DMI has always been challenging and has only been experimentally confirmed in recent years . Studies have demonstrated that the DMI strength in hybrid ferroelectric-ferromagnetic systems can be effectively manipulated by external stimuli such as electric fields and strain. ,− These factors can bring about significant alterations to the DMI of the system. For instance, Srivastava et al achieved a 130% variation of DMI (about 0.1 ± 0.04 mJ/m 2 ) with an electric field in Ta/FeCoB/TaO x trilayer through the Brillouin Light Spectroscopy (BLS) method .…”