The rapid expansion of data generation is challenging the capabilities of traditional charge-based electronics, such as smartphones and laptops. In response, researchers at Argonne National Laboratory are investigating alternative technologies that utilize electron spin. Spintronics, which exploits electron spin rather than charge, addresses the limitations of conventional electronics by enabling low-energy data switching, non-volatile memory, and ultra-dense storage.
Electrons possess a property known as spin, which generates a small magnetic field oriented either upward or downward, similarly to a compass needle. These magnetic positions serve as information carriers. Future advancements in spintronics rely on the precise control of electron spins at the nanoscale, which is thousands of times thinner than a human hair.
Recent research at Argonne National Laboratory has revealed the behavior of magnetic domains within these two-dimensional materials. The research team investigated how variations in nanoscale magnet thickness influence domain formation, switching mechanisms, and the overall density and size of magnetic domains.
“AI’s growth is pushing the limits of today’s microelectronics. Spintronics could enable faster, smaller, more efficient devices to meet the demand,” said Amanda Petford-Long, materials science researcher emeritus, an Argonne Distinguished Fellow, and a co-author of the study published in Advanced Functional Materials.
The researchers focused on Fe3GeTe2 (FGT), a Van der Waals ferromagnet exhibiting strong magnetic properties that are desirable for spintronic applications. Van der Waals magnets are ultrathin materials, only a few atoms thick, making them highly suitable for constructing spintronic devices that demand precise control at small scales. These materials offer a promising foundation for the development of future electronics and advanced data storage technologies. Because FGT is magnetic only at very low temperatures, it was cooled to approximately -173°C (100 K) using liquid nitrogen, and a magnetic field was applied during cooling to establish well-defined magnetic patterns.
Direct imaging using cryogenic Lorentz Transmission Electron Microscopy (cryo-LTEM) allowed the team to observe spin organization and domain formation in ultrathin FGT in real time. The results demonstrated that material thickness and magnetic field strength govern the size, density, and evolution of skyrmions, which are small, stable magnetic whirlpools that require minimal energy to move. This control is essential for reducing skyrmion size to accommodate the miniature scale required by modern electronic devices.
“If engineers can reliably tune skyrmion size and density, they can begin building the kinds of spintronic technologies that have long been imagined. Those with ultra‑dense memory, low‑power processors, and magnetic storage far beyond the capabilities of today’s hard drives,” said Charudatta Phatak, interim director and group leader in Argonne’s Materials Science division and a study co-author.
Argonne’s research offers a future framework for predicting domain patterns and behavior based on material thickness and cooling parameters. The ability to control magnetism in atomically thin materials will pave the way for the development of energy-efficient, spin-based computing technologies.
