Scientists unveil a new way to control magnetism in super-thin materials

A team of researchers has discovered a powerful new method to control magnetic behaviour in ultra-thin materials - an advance that could lead to faster, smaller, and more energy-efficient technology, from computer memory to next-generation electronics.

The study, published in Nature Materials, introduces a way to precisely tune magnetism by using the natural structure of a material called CrPS₄, a stable and flexible compound just a few atoms thick. This breakthrough opens a window into the invisible world of atomic-scale magnetism, solving a long-standing scientific problem and providing a new platform for designing smart magnetic devices.

What’s the big deal?

You’ve probably heard of magnets sticking to your fridge, but magnetism is also the core of how digital memory works. In computers, tiny magnetic regions are used to store information - whether a ‘bit’ is a 0 or a 1 depends on the direction of its magnetic field.

One way scientists control these magnetic fields is through something called exchange bias - a tiny shift in the magnetic behaviour that helps keep the memory stable and prevents data loss. But until now, this effect was tricky to study and even harder to control because it happens at buried, imperfect interfaces between different materials.

A new solution from a single material

The new research flips the script. Instead of stacking different materials on top of each other, the team discovered they could achieve the same control within a single material. In ultra-thin flakes of CrPS₄, layers of atoms naturally form regions with different magnetic properties - some behave like antiferromagnets (AFM), which have opposing magnetic directions and cancel each other out, and others act like ferromagnets (FM), where all the spins align.

Dr Elton Santos from the School’s Institute for Condensed Matter and Complex Systems said:

These regions line up side by side like lanes on a highway. The border between them forms a perfect interface, allowing us to study and control magnetic behaviour with incredible precision.

How did they do it?

The team used a cutting-edge imaging technique called nitrogen-vacancy (NV) centre magnetometry - a kind of ultra-sensitive magnetic ‘microscope’ that uses diamond sensors to visualize tiny magnetic fields. With this, they could see how the magnetic domains formed, interacted, and shifted at the boundaries between different layers of CrPS₄.

They found that by changing the arrangement of these layers, they could turn the magnetic bias on or off, like flipping a switch. It’s a controllable, reversible process - something that could be very useful for future technologies.

Why it matters

This discovery doesn’t just deepen our understanding of magnetism - it lays the groundwork for building smarter, smaller, and more reliable magnetic devices. It could help engineers design ultra-compact memory chips, reconfigurable sensors, or even quantum devices based on magnetic principles.

And since CrPS₄ is stable in air and easy to work with, it’s an ideal candidate for real-world applications, not just lab experiments.

Dr Santos explains:

This work gives us a transparent and reliable platform to understand and engineer magnetism at the atomic scale. It opens the door to a whole new class of magnetic technologies.