No abstract

We report the dependence of the domain wall depinning field, domain wall velocity, including anisotropy direction, and magnetic properties on the oxidized aluminum thickness of perpendicularly magnetized asymmetric Pt/Co/AlOx trilayers. We also adopt the low-temperature magneto-transport measurement technique to investigate the amount of oxygen at the Co/AlOx interface of our magnetic thin films. At the lowest temperature of 25 K, it is found that the coercivity for the 5 nm aluminum thickness sample is very close to the average value and coercivity diminished above and below this critical aluminum thickness, hinting at a large variation in CoOx content at the interface. This tendency is also consistent with the modification of the depinning fields, coercive fields, and surface roughness measured at room temperature. Our results highlight an efficient way of controlling the depinning fields and other magnetic characteristics, which is important for stabilizing and driving magnetic spin textures and applicable to energy-efficient next-generation spintronics devices.

No 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.