Manchester Scientists Uncover How 2D Materials Control Magnetic Energy Loss

Scientists at the University of Manchester have found that placing magnetic films on atomically thin molybdenum disulfide (MoS₂) alters how they lose energy. This discovery could advance 2D-material spintronics toward practical devices.

The research indicates that growing permalloy, a magnetic alloy, on ultra-thin MoS₂ changes the film's internal crystal structure. This structural alteration impacts how and where magnetic spins lose energy.

By distinguishing between energy losses at the film's surface and those within its internal structure, the team offers new design insights for devices utilizing two-dimensional (2D) materials to control magnetism more efficiently.

Scalability for Practical Applications

The study utilized large-area, manufacturing-compatible MoS₂, demonstrating that these effects are applicable beyond laboratory settings and are relevant for scalable spintronic technologies.

Published in Physical Review Applied, the findings show that transition-metal dichalcogenides (TMDs) can modify the fundamental properties of magnetic films. The results emphasize the need for careful comparison with control materials when evaluating the impact of 2D layers on magnetic behavior.

The Challenge of Spintronics

Spintronics, which uses both the charge and spin of electrons, offers an alternative to conventional electronics for information storage and processing. A key challenge in spintronics is energy loss, as magnetic spins dissipate energy as heat, which limits device speed and efficiency.

Researchers observed that the clean interface between permalloy and MoS₂ reduces energy loss at the surface of the magnetic film. Simultaneously, minor changes within the film's crystal structure slightly increase internal energy loss. This distinction helped explain previously conflicting results from other studies on 2D materials and magnetism.

Measuring Energy Dissipation

The team employed ferromagnetic resonance, a technique that measures how quickly wobbling spins in a magnetic material fade, to determine energy dissipation. Varying the magnetic layer's thickness allowed them to differentiate between surface and bulk film losses.

Towards Next-Generation Memory

These results suggest new methods for designing lower-power, faster spintronic memory by engineering material interfaces to minimize energy loss while maintaining performance. Dr. Henry De Libero, the lead author, stated that the fundamental effects of 2D materials on magnetic thin films are still largely unexplored, and understanding energy loss is critical for next-generation memory technologies.

The study concludes that 2D materials do not universally increase energy loss and can reduce it with the appropriate interface.