Mar 11, 2019
(Nanowerk News) Spin-orbitronic is one of the latest technologies to encode digital information. This technology, which provides high processing speed, high capacity for data storage, and very low energy consumption, can be applied in certain materials to generate magnetic configurations that are very stable, but can still be controlled and moved quickly with small electrical currents.
Now, a team led by Graphene Flagship partner IMDEA Nanociencia has developed a new methodology to prepare graphene spin-orbitronic systems. The resulting structures are considered very promising for future 'spin-orbitronic' storage devices.
Spin-orbitronic exploits both the charge of the electron (electronics) and its spin (spintronics) and the interaction of the spin with its orbital motion, offering a multitude of properties that are relevant to magnetism.
The new devices are made of graphene films – a single atom thick graphite layer – placed on ferromagnetic material: cobalt, arranged around a platinum layer with a certain crystallographic orientation. The results were recently published in Nano Letters ("Unraveling Dzyaloshinskii–Moriya Interaction and Chiral Nature of Graphene/Cobalt Interface").
Paolo Perna, lead author of the study from Graphene Flagship partner IMDEA Nanociencia, explains the advantages of the cobalt-graphene symbiosis: "On one hand, the exceptional properties of graphene allow us to obtain a homogeneous, flat and protected magnetic layer, which is also atomically perfect. However, what matters most," he goes on to emphasize, "we achieve two key magnetic properties: an improvement in the magnetic anisotropy of cobalt – its spins are preferably oriented in a certain direction – and a strong interaction called Dzyaloshinskii-Moriya, which allows the presence of chiral magnetic structures – which do not overlap with its specular image."
Diagram of stacked graphene, cobalt (Co) and platinum (Pt) layers with magnetic interaction vectors. (Image: Adrián Gudín, Paolo Perna, IMDEA Nanociencia, (© American Chemical Society)